jQuery.inArray()
Search for a specified value within an array and return its index (or -1 if not found).
jQuery.inArray(value, array, fromIndex)π‘’ Number
value
Anything The value to search for.
array
Array An array through which to search.
fromIndex
Number The index of the array at which to begin the search. The default is 0, which will search the whole array.The $.inArray() method is similar to JavaScript's native .indexOf() method in that it returns -1 when it doesn't find a match. If the first element within the array matches value, $.inArray() returns 0.
Because JavaScript treats 0 as loosely equal to false (i.e. 0 == false, but 0 !== false), to check for the presence of value within array, you need to check if it's not equal to (or greater than) -1.
The comparison between values is strict. The following will return -1 (not found) because a number is being searched in an array of strings:
$.inArray(5 + 5, ["8", "9", "10", 10 + ""]);
Report the index of some elements in the array.
JS
<div>"John" found at <span></span></div>
<div>4 found at <span></span></div>
<div>"Karl" not found, so <span></span></div>
<div>"Pete" is in the array, but not at or after index 2, so <span></span></div>
CSS
div {
color: blue;
}
span {
color: red;
}
HTML
var arr = [4, "Pete", 8, "John"];
var $spans = $("span");
$spans.eq(0).text(jQuery.inArray("John", arr));
$spans.eq(1).text(jQuery.inArray(4, arr));
$spans.eq(2).text(jQuery.inArray("Karl", arr));
$spans.eq(3).text(jQuery.inArray("Pete", arr, 2));
DEMO