Showing 4,375 of 4,375 total issues
First header should be a top level header Open
## The short answer- Read upRead up
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MD002 - First header should be a top level header
Tags: headers
Aliases: first-header-h1
Parameters: level (number; default 1)
This rule is triggered when the first header in the document isn't a h1 header:
## This isn't a H1 header
### Another headerThe first header in the document should be a h1 header:
# Start with a H1 header
## Then use a H2 for subsectionsLine length Open
As mentioned already, we simply need to use `Object.keys()` to get all the properties of the object and then use `Array.prototype.forEach()` to run the provided function for each key-value pair. The callback should receive **three arguments** - the value, the key and the object itself.- Read upRead up
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MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
As stated already, compatibility shouldn't be an issue, so we're not going to delve into that. However, there's a notable oddity concerning the method's arguments. As it turns out, **Firefox** used to support an optional `forceGet` boolean argument, which you might come across in older code. This means that passing a value of `true` to the method would bypass the **browser's cache**.- Read upRead up
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MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
First header should be a top level header Open
## Hidden state- Read upRead up
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MD002 - First header should be a top level header
Tags: headers
Aliases: first-header-h1
Parameters: level (number; default 1)
This rule is triggered when the first header in the document isn't a h1 header:
## This isn't a H1 header
### Another headerThe first header in the document should be a h1 header:
# Start with a H1 header
## Then use a H2 for subsectionsLine length Open
[`Array.prototype.map()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map) creates a new array by applying the provided transformation to each element of the original array. The result is an array with the same length as the original array and elements transformed based on the provided function.- Read upRead up
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MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
I strongly recommend you read the [previous article on closures](/js/s/closures) if you haven't already. Instead of rehashing the same information, I would like to discuss the dangers of using closures and present my view on the topic.- Read upRead up
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MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
- Define a `remove()` method, that uses the `preOrderTraversal()` method and `Array.prototype.filter()` to remove a `TreeNode` from the tree.- Read upRead up
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MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
[`Array.prototype.filter()`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter) creates a new array by using a filtering function to keep only elements that return `true` based on that function. The result is an array with equal or less than the original array's length, containing a subset of the same elements as the original array.- Read upRead up
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MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
excerpt: Understand why JavaScript's built-in array sorting is not stable and how to implement a stable sorting algorithm.- Read upRead up
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MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
Finally, if you only need to **switch a class on and off**, you can use the `DOMTokenList.toggle()` method.- Read upRead up
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MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
2. Create an empty **2D array**. Use a `for` loop to iterate over the letters of the target string and a nested `for` loop to iterate over the letters of the source string.- Read upRead up
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MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
Subtraction can take us further still, calculating the date difference in days. Without taking timezones into account, we can simply divide the difference in milliseconds by the number of milliseconds in a day (`1000 * 60 * 60 * 24`).- Read upRead up
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MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Ordered list item prefix Open
5. Return the **last element of the last row** of the produced array. This is the Levenshtein distance between the two strings.- Read upRead up
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MD029 - Ordered list item prefix
Tags: ol
Aliases: ol-prefix
Parameters: style ("one", "ordered"; default "one")
This rule is triggered on ordered lists that do not either start with '1.' or do not have a prefix that increases in numerical order (depending on the configured style, which defaults to 'one').
Example valid list if the style is configured as 'one':
1. Do this.
1. Do that.
1. Done.Example valid list if the style is configured as 'ordered':
1. Do this.
2. Do that.
3. Done.Line length Open
> The above snippet may be ill-suited for real-life scenarios, as it **doesn't take official holidays into account**. It's recommended to tweak the weekday check to include a list of known holidays, too, if you plan on using it in production.- Read upRead up
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MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
JavaScript uses **type coercion** (implicit conversion of values from one data type to another) in Boolean contexts, such as conditionals. This means that values are considered either truthy (evaluate to `true`) or falsy (evaluate to `false`) depending on how they are evaluated in a Boolean context.- Read upRead up
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MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
First header should be a top level header Open
## Mutative methods- Read upRead up
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MD002 - First header should be a top level header
Tags: headers
Aliases: first-header-h1
Parameters: level (number; default 1)
This rule is triggered when the first header in the document isn't a h1 header:
## This isn't a H1 header
### Another headerThe first header in the document should be a h1 header:
# Start with a H1 header
## Then use a H2 for subsectionsLine length Open
The solution to this problem, and the first trick that you can use to speed up recursive functions, is to use memoization. We already published [a great blog post on memoization](/js/s/memoization/) a little while back, so be sure to check it out to learn more about the subject. Here's our `fibonacciNumber` function, using memoization:- Read upRead up
- Exclude checks
MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
Apart from the last two types, all other types are considered **primitive types**. Primitive types are **immutable**, meaning that their values cannot be changed. Objects and functions, on the other hand, are **mutable**, meaning that their values can be changed.- Read upRead up
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MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
Primitives are generally easier to typecheck than objects and functions. This is because primitives are immutable, meaning that their values cannot be changed. Thus, we can simply compare the type of a value to the type we want to check for. This is where the `typeof` operator comes in handy.- Read upRead up
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MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
The rest of the process is pretty much the same. The only notable exception is that the **last chunk's calculation** is slightly different, as it needs to include the remaining elements, shall the remainder be less than the minimum chunk size.- Read upRead up
- Exclude checks
MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.