JavaScript Program to Insert a String Within a Specific Position in Another String

JavaScript Program to Insert a String Within a Specific Position in Another String

Write a JavaScript program to insert a string within a specific position in another string.



Source Code
<html>
<head>
    <title>Insert a string within a specific position in another string</title>
</head>
<body>
<script>
    function insert(main_string, ins_string, pos) 
    {
        if(typeof(pos) == "undefined") 
        {
            pos = 0;
        }
        if(typeof(ins_string) == "undefined") 
        {
            ins_string = '';
        }
        return main_string.slice(0, pos) + ins_string + main_string.slice(pos);
    }
    var main_string = "Welcome to JavaScript"
    var ins_string = " the world of "
    var pos = 10
    var final_string = insert(main_string, ins_string, pos)
    document.write("Main String: <b>" + main_string + "</b><br/>");
    document.write("String to insert: <b>" + ins_string + "</b><br/>");
    document.write("Position of string: <b>" + pos + "</b><br/>");
    document.write("Final string: <b>" + final_string + "</b>");
</script>
</body>
</html>
Output