JavaScript: String Methods

String methods in JavaScript; In this javascript tutorial, you will learn most useful and important string methods/functions in javascript. Javascript string methods help to manipulate strings in javascript.

We will demonstrate javascript string methods like javascript string replace, javascript string contains, javascript string length, javascript string concatenation, javascript string substring, remove the character from string javascript, javascript string uppercase, javascript string lowercase, string trim, tostring method, a match in the string, split string in javascript,
javascript string substr, trim string, array to comma-separated string, etc.

You need to know some of the most important and useful javascript string methods/Functions.

JavaScript String Methods

The following important and useful javascript string methods:

• Length Method
• toLocaleLowerCase() Method
• toLocaleLowerCase() Method
• indexOf() Method
• search() Method
• slice() Method
• substring() Method
• substr() Method
• replace() Method
• includes() Method
• concat() Method
• charAt() Method
• charCodeAt() Method
• lastIndexOf() Method
• trim() Method
• match() Method
• split() Method
• toString() Method
• valueOf() Method

1. length() Method

It is used to count the number of characters in a string javascript.

Example

var lng = "Hello Tutsmake";
var x = lng.length;

Output 

// return 
14

2. toLocaleLowerCase() Method

The javascript toLocaleLowerCase() is used to changed string into lower case.

Example

var str = "Hello Dev!";
var res = str.toLocaleLowerCase();

Output
// return
hello dev!

3. toLocaleUpperCase() Method

The javascript toLocaleUpperCase () is used to changed string into upper case.

Example

var str = "Hello Dev!";
var res = str.toLocaleUpperCase();

Output
// return
HELLO DEV!

4. indexof() Method

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

Example

 var txt = "Lets find where 'pen' occurs!";
 var test = txt.indexOf("pen");

Output

// return 
17

5. search() Method

The javascript search () method searches a string for the specified value, and returns the status of the match.

Example

var str = "hello dev!"; 
var n = str.search("dev");

Output
//Return
6

6. slice() Method

The slice () method removes the parts of a string and returns the extracted parts to a new string.

Use the Start and End Ultimate to specify the part of the string that you want to remove.

Example

var str = "Developers world!"; 
var res = str.slice(0, 10);

Output
// return
Developers

7. substring() Method

The Javascript substring() method is used to removes the characters from one string, between two specified indices, and returns the new substring.

Example

  var str = "Hello dev!";
  var res = str.substring(1, 4);

Output
//return
ell

8. substr() Method

A string substr() method begins on the character in the specified position, and returns the specified number of characters.

Example

 var str = "Hello dev!";
 var res = str.substring(1, 4);

Output
//return
ello

9. replace() Method

The Javascript replace() changes the defined value to an another value:

Example

var str = "Hello Dev!";
var res = str.replace("Dev", "World");

Output
// return
Hello World

10. includes() Method

The includes() method is used to determine whether a string contains the characters of a specified string or not. If is exist return true or not return false.

Example

var str = "Hello world, my name is tutsmake.";
var n = str.includes("name");

Output
// return 
True

More Examples of javascript Include() function

11. concat() Method

The concat() method is used for join two or more strings.

Example

var str1 = "Hello ";
var str2 = "keny!";
var res = str1.concat(str2);

Output
// return
Hello Keny

12. charAt() Method

The Javascript charAt() is used to take a character to a described index location:

Example

var txt = "Hello Keny";
txt.charAt(0);

Output
// return
H

13. charCodeAt() Method

The charCodeAt() method returns the Unicode of the character at a specified index in a string:

Example

var str = "TEST";
str.charCodeAt(0); 

Output
// return
84

14. lastIndexOf () Method

The lastIndexOf() the method returns the index of the last occurrence of a specified text in a string:

Example

var str = "Your are talented dev";
var pos = str.lastIndexOf("dev");

Output
// return
18

15. trim() Method

The javascript trim() method removes whitespace from both sides of a given string:

Example

var str = "       Trim Both Side        ";
alert(str.trim());

Output
// return
Trim Both Side

16. match() Method

The match() method searches a string for a match against a regular expression, and returns the matches, as an Array object.

Example

  var str = "lopersum lopersum lopersum lopersum."; 
  var res = str.match(/sum/g);

Output
// return
 sum,sum,sum,sum

17. split Method

The javascript split method, which is used to convert string to an array:

Example

var str = "1,2,3,4,5";
var arr = str.split(",");
document.write(arr[0]);
document.write("<br>");
document.write(arr[1]);

Output
// return
1
2

18. toString() Method

The javascript toString() method returns the value of a String object.

Example

var str = "javaScript World!";
var res = str.toString();

Output
// return
javaScript World!

19. valueOf() Method

The javascript valueOf() method, which is used to gets the primitive value of a String object.

Example

  var str = "javaScript World!";
  var res = str.valueOf();

Output
// return
javaScript World!