JavaScript String Methods

Strings are texts that help in holding data that can be represented. A JavaScript string stores a series of characters like “GeeksforGeeks”. A string can be any text inside double or single quotes.

JavaScript String Methods and Property: String methods and properties are important to perform any operation on the given string, the string search methods have a separate article for better understanding. Below we have described a few important methods with the proper example code.

• String length Property
• String indexOf() Method
• String lastIndexOf() Method

String indexes start from 0. The first character is in position 0 and the second in 1 and the same follows. We can call any of the pre-defined methods of JavaScript as it automatically converts from string primitive to objects.

Example:

 var gfg= "geeksforgeeks";

JavaScript String length Property: This property returns the number of characters present in the string. In the case of an array, this property returns the number of elements present in the array.

Example: This example describes the JavaScript String Length property.

Output:

3

JavaScript String indexOf() Method: This method returns the index of the last occurrence of a specified value in a string, or -1 if the value is not found.

Example: This example describes the JavaScript String indexOf() method.

Output:

7

JavaScript String lastIndexOf() Method: This method returns the index of the last occurrence of a specified value in a string, or -1 if the value is not found.

Example: This example describes the JavaScript String lastIndexOf() method.

Output:

8

JavaScript slice(startIndex, endIndex) Method: This method extracts a part of the string based on the given starting-index and ending-index and returns a new string.

Example: This example describes the JavaScript String slice() method.

Output:

Geeks
for
Geeks

JavaScript substring(startIndex, endIndex) Method: This method returns the part of the given string from the start index to the end index. Indexing start from zero (0).

Output:

Power

JavaScript substr(start, length) Method: This method returns the specified number of characters from the specified index from the given string. It basically extracts a part of the original string.

Power

JavaScript replace(replaceValue, replaceWithValue) Method: This method replaces a part of the given string with another string or a regular expression. The original string will remain unchanged.

Output:

Mind, Space, Soul

JavaScript replaceAll(regexp | substr , newSubstr | function) Method: This method returns a new string after replacing all the matches of a string with a specified string or a regular expression. The original string is left unchanged after this operation.

Output:

Mind, Space, Space,  Soul

JavaScript toUpperCase(stringVariable) Method: This method converts all the characters present in the String to upper case and returns a new String with all characters in upper case. This method accepts single parameter stringVariable string that you want to convert in upper case.

Example: This example describes the JavaScript String toUpperCase() method.

Output:

STANDS-FOR-GEEKSFORGEEKS

JavaScript toLowerCase(stringVariable) Method: This method converts all the characters present in the so lowercase and returns a new string with all the characters in lowercase.

tring t

Example: This example describes the JavaScript String toLowerCase() method.

Output:

stands-for-geeksforgeeks

JavaScript concat(objectOfString) Method: This method combines the text of two strings and returns a new combined or joined string. To concatenate two strings, we use concat() method on one object of string and send another object of string as a parameter. This method accepts one argument. The variable contains text in double quotes or single quotes.

Example: This example describes the JavaScript String concat() method.

Output:

GFG stands for GeeksforGeeks

JavaScript trim() Method: This method is used to remove either white spaces from the given string. This method returns a new string with removed white spaces. This method is called on a String object. This method doesn’t accept any parameter.

Example: This example describes the JavaScript String trim() method.

Output:

7
3

JavaScript trimStart() Method: This method removes whitespace from the beginning of a string. The value of the string is not modified in any manner, including any whitespace present after the string.

Output:

  Soul
Soul

JavaScript trimEnd() Method: This method removes white space from the end of a string. The value of the string is not modified in any manner, including any white-space present before the string.

Output:

Soul    
Soul

JavaScript padStart() Method: This method pad a string with another string until it reaches the given length. The padding is applied from the left end of the string.

Output:

Mind Soul

JavaScript padEnd() Method: This method pad a string with another string until it reaches the given length. The padding is applied from the right end of the string.

Output:

Soul Power

JavaScript charAt(indexOfCharacter) Method: This method returns the character at the specified index. String in JavaScript has zero-based indexing.

Example: This example describes the JavaScript string charAt() method.

Output:

GeeksforGeeks
GfG is the best platform to learn 
and experience Computer Science.
G
s

JavaScript charCodeAt(indexOfCharacter) Method: This method returns a number that represents the Unicode value of the character at the specified index. This method accepts one argument.

Example: This example describes the JavaScript String charCodeAt() Method.

Output:

71
115

JavaScript split(character) Method: This method splits the string into an array of sub-strings. This method returns an array. This method accepts a single parameter character on which you want to split the string.

Example: This example describes the JavaScript String split() method.

Output:

['stands', 'for', 'GeeksforGeeks']