nth-child property

Definition and Usage

The :nth-child(an+b) CSS pseudo-class matches an element that has an+b-1 siblings before it in the document tree, for a given positive or zero value for n, and has a parent element.

This can more clearly be described this way: the matching element is the bth child of an element after all its children have been split into groups of a elements each.

The values a and b must both be integers, and the index of an element’s first child is 1.

In other words, this class matches all children whose index fall in the set { an + b; n = 0, 1, 2, … }.

Among other things, this allows selectors to match every other row in a table.

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Syntax

element:nth-child(an + b) { style properties }

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Examples

Example selectors

tr:nth-child(2n+1)

Represents the odd rows of an HTML table.

tr:nth-child(odd)

Represents the odd rows of an HTML table.

tr:nth-child(2n)

Represents the even rows of an HTML table.

tr:nth-child(even)

Represents the even rows of an HTML table.

span:nth-child(0n+1)

Represents a span element which is the first child of its parent; this is the same as the :first-child selector.

span:nth-child(1)

Equivalent to the above.

span:nth-child(-n+3)

Matches if the element is one of the first three children of its parent and also a span.

Odd Selector Example

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Compatibility

Desktop browsers

Mobile browsers