Skip to content
Related Articles

Related Articles

Improve Article

What are the builtin strings in JavaScript ?

  • Last Updated : 23 Apr, 2020

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 lower case.
  • 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: The methods that are defined by the user to perform a particular task.



  • 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.

Example: Search() method.




<p id="demo"></p>
  
function myFunction() {
  var str = "Welcome to GeeksforGeeks!"
  var a= str.search("GeeksforGeeks");
  document.getElementById("demo").innerHTML = a;
}

Output:

11

Example: split() method.




<p id="demo"></p>
  
function myFunction() {
  var str = "How are you feeling today?";
  var res = str.split(" ");
  document.getElementById("demo").innerHTML = res;
}

Output:

How, are, you, feeling, today?

Example: startsWith() method.




<p id="demo"></p>
  
function myFunction() {
  var str = "Hello world, welcome to the universe.";
  var n = str.startsWith("Hello");
  document.getElementById("demo").innerHTML = n;
}

Output:

true



My Personal Notes arrow_drop_up