Introduction to JavaScript LastIndexOf method (calculates where the specified character last appears in the string) _ Basics

JavaScript LastIndexOf method

The LastIndexOf method computes the last occurrence of the specified string in the entire string and returns the value. The syntax is as follows:

Copy Code code as follows:

Str_object.lastindexof (search, start)

Parameter description:

Parameters	Description
Str_object	The string to manipulate (object)
Search	Necessary. The string to retrieve
Start	Optional. Specifies the location at which to start retrieving, such as omitting the argument, and then starting from the last character of the string

Tip: The string is counted starting from 0.

LastIndexOf Method Instance

Copy Code code as follows:

<script language= "JavaScript" >

var str = "Www.jb51.net";
document.write (Str.lastindexof (".") + "<br/>");
document.write (Str.lastindexof (".", 5) + "<br/>");
document.write (Str.lastindexof (".", 10));

</script>

Run the example and output:

Copy Code code as follows:

9
3
9

Note that in the example above, the second parameter is 5, the first one is actually found. Symbol, that is, searching in the www.5 string.


LastIndexOf is case sensitive, and if the string value to retrieve does not appear, the method returns-1.