What are the builtin strings in JavaScript ?

A sequence of letters, special characters, numbers, etc., or a combination of all of them is known as a string. Strings are created by enclosing the string characters within a single quote (‘) or within double quotes (“). 

Syntax:

var myString = 'Good Morning123!'; // Single quoted string
var myString = "Good Morning123!"; // Double quoted string

In Javascript, many string methods are either built-in or user-defined. Built-in string methods are the methods that are present in any programming language library. 

Built-in string methods of JavaScript:

• search(): It is used to search a string for a specific value or an expression. It returns the position of the match.
• split(): It is used to split a string into an array of substrings.
• startsWith(): It is used to check whether a string begins with the specified characters.
• slice(): It is used to extract a part of a string and return a new string.
• concat(): It is used to combine texts of two strings and return a new string.
• charAt(): It is used to return the character at the specified index.
• indexOf(): It is used to return the index, within the string object, which occurs first, of the specified value. It returns -1 if the object is not found.
• lastIndexOf(): It is used to return the index, within the string object, which occurs last, of the specified value. It returns -1 if the object is not found.
• match(): It is used to match a regular expression against a string.
• replace(): It is used to find a match between a regular expression and a string. The matched substring is replaced with a new substring.
• substr(): It is used to return the characters in a string, beginning at the specified location, through the specified number of characters.
• substring(): It is used to return the characters in a string between the two specified indexes.
• toLowerCase(): It is used to convert the string value which is called, to lowercase.
• toUpperCase(): It is used to convert the string value which is called, to upper case.
• valueOf(): It is used to return the primitive value of the specified object.
• User-defined string methods in JavaScript:
  • logIt(): It is used to log a parameter back to the console when the code is executed.
  • return(): It is used to return a specific value, explicitly.

Below are some examples demonstrating the use of the Javascript string methods.

Example: This example shows the use of the Javascript string search() method. 

HTML

<p id="demo"></p>

<script type="text/javascript" charset="utf-8">
    function myFunction() {
    var str = "Welcome to GeeksforGeeks!";
    var a= str.search("GeeksforGeeks");
    document.getElementById("demo").innerHTML = a;
    }
    myFunction()
</script>

Output:

11

Example: This example shows the use of the Javascript string split() method. 

javascript

<p id="demo"></p>

<script type="text/javascript" charset="utf-8">
    function myFunction() {
      var str = "How are you feeling today?";
      var res = str.split(" ");
      document.getElementById("demo").innerHTML = res;
    }
    myFunction()
</script>

Output:

How, are, you, feeling, today?

Example: This example shows the use of the Javascript string startsWith() method. 

javascript

<p id="demo"></p>

<script type="text/javascript" charset="utf-8">
    function myFunction() {
      var str = "Hello world, welcome to the universe.";
      var n = str.startsWith("Hello");
      document.getElementById("demo").innerHTML = n;
    }
    myFunction()
</script>

Output:

true