Use of indexOf and charAt in javascript

indexOf():

The indexOf() method returns the position of the first occurrence of a specified value in a string.

This method returns -1 if the value to search for never occurs.

example : 

<script type="text/javascript">

var str="Hello world!";
document.write(str.indexOf("d") + "<br />");
document.write(str.indexOf("WORLD") + "<br />");
document.write(str.indexOf("world"));

</script>

Output :

10
-1
6

charAt()

The charAt() method returns the character at the specified index in a string.

The index of the first character is 0, and the index of the last character in a string called "txt", is txt.length-1



<script type="text/javascript">

var str = "Hello world!";
document.write("First character: " + str.charAt(0) + "<br />");
document.write("Last character: " + str.charAt(str.length-1));

</script>




Output :


First character: H

Last character: !