First header should be a top level header Open
## Remove or append an element in an array of primitives- Read upRead up
- Exclude checks
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
Using `Array.prototype.includes()`, you can **check if the element is already in the array**. If it is, you can use `Array.prototype.filter()` to **remove** it. If it's not, you can use the spread operator (`...`) to **append** it to the array.- 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
I've often found myself needing to toggle - add or remove - an element in an array based on its presence. While JavaScript has no built-in method for this, it's pretty simple to implement.- 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
Given that both branches of the ternary operator create **shallow clones**, neither case mutates the original array, instead returning a **new array** with the desired changes.- 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
When working with arrays of objects, you can use a similar approach. However, you'll need to provide a **comparison function** to determine if the object already exists in the array.- 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
Adding a default value for the `compFn` parameter allows you to use the `===` operator by default, which in turn allows you to **omit the comparison function** when working with arrays of primitives.- 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
Given a comparison function, `compFn`, you can use `Array.prototype.filter()` to **remove** any matching objects. Then, using `Array.prototype.length`, you can determine if the object was removed and **append** it using the spread operator (`...`), if necessary.- 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
excerpt: Remove an element from an array if it's included in the array, or push it to the array if it isn't.- 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.