JavaScript » String » lastIndexOf


When called from a String object, this method returns the index of the last occurance of the specified searchValue argument, searching backwards from the specified fromIndex argument.

If the searchValue is not found, a value of -1 is returned. Characters in the string are indexed from left to right with the first character indexed as 0 and the last as String.length-1. Note that this method is case sensitive as shown in the example below.


myString = new String("")
document.writeln("<br>" + myString.lastIndexOf("u",5))
document.writeln("<br>" + myString.lastIndexOf("com",6))
document.writeln("<br>" + myString.lastIndexOf("Com"))

This example uses the lastIndexOf method to find the index values of four different character strings within the myString object. Note that the third example returns -1 because there is no occurrence of the specified string before index value 6, and the fourth example returns -1 because the case of one of the characters does not match.

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