This method returns the index within the calling String object of the first occurrence of the specified value, starting the search at fromIndex or -1 if the value is not found.
searchValue − A string representing the value to search for.
fromIndex − The location within the calling string to start the search from. It can be any integer between 0 and the length of the string. The default value is 0.
Returns the index of the found occurrence, otherwise -1 if not found.
var str1 = new String( "This is string one" ); var index = str1.indexOf( "string" ); console.log("indexOf found String :" + index ); var index = str1.indexOf( "one" ); console.log("indexOf found String :" + index );
Its output is as follows −
indexOf found String :8 indexOf found String :15