14 Jan

The indexOf finds the location of a set of characters inside a string and tells you where the substring starts.

var the_word = “monkey”; //Let’s start with the word “monkey.”

var location_of_m = the_word.indexOf(“m”); // The location_of_m will be “0,”

var location_of_key = the_word.indexOf(“key”); // The location_of_key is “3”

var cheeky = the_word.indexOf(“q”); // The cheeky is “-1” coz there’s no letter “q” in “monkey.”

A more realistic use of indexOf is:

var the_email = prompt(“What’s your email address?”, “”);

var the_at_is_at = the_email.indexOf(“@”);

if (the_at_is_at == -1)
alert(“You loser, email addresses must have @ signs in them.”);


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