Javascript InStr Function
The string.indexOf function is used as instr function in javascript.
syntax:
object.indexOf(searchValue,[fromIndex])
When called from a String object, this method returns the index of the first occurance of the specified searchValue argument, starting 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.
The following code uses the indexOf method to find the index values of three different character strings within the myString object. Note that the third example returns -1 because the case of one of the characters does not match.
Code:
myString = new String(”webdevelopers.com”)
document.writeln(myString.indexOf(”developers”))
document.writeln(”<br>” + myString.indexOf(”com”))
document.writeln(”<br>” + myString.indexOf(”Com”))
Output:
3
14
-1
