JavaScript String Methods

JavaScript string methods :

charAt()

The charAt() method returns the character at the specified index in a string. The index of the first character is 0, the second character is 1, and so on.


var str = "HELLO WORLD";
var result = str.charAt(0);

console.log(result)
//OUTPUT: H

charCodeAt()

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


var str = "HELLO WORLD";
var result = str.charCodeAt(0);

console.log(result)
//OUTPUT: 72

concat()

The concat() method is used to join two or more strings. This method does not change the existing strings, but returns a new string containing the text of the joined strings.


var str1 = "HELLO ";
var str2 = "WORLD";
var result = str1.concat(str2);

console.log(result)
//OUTPUT:HELLO WORLD

endsWith()

The endsWith() method determines whether a string ends with the characters of a specified string. This method returns true if the string ends with the characters, and false if not.


var str = "HELLO WORLD,I like Coding";

var result = str.endsWith("Coding");

console.log(result)
//OUTPUT: true

fromCharCode()

The fromCharCode() method converts Unicode values into characters. This is a static method of the String object, and the syntax is always String. fromCharCode()



var result = str.fromCharCode(65);

console.log(result)
//OUTPUT: A

includes()

The includes() method determines whether a string contains the characters of a specified string.


var str = "HELLO WORLD,I like Coding";

var result = str.includes("like");

console.log(result)
//OUTPUT: true

indexOf()

The indexOf() method returns the position of the first occurrence of a specified value in a string. This method returns -1 if the value to search for never occurs.


var str = "HELLO WORLD, I like Coding";

var result = str.indexOf("I");

console.log(result)
//OUTPUT: 13

lastIndexOf()

The lastIndexOf() method returns the position of the last occurrence of a specified value in a string. The string is searched from the end to the beginning, but returns the index starting at the beginning, at position 0.


var str = "HELLO WORLD, I like Coding";

var result = str.lastIndexOf("Coding");

console.log(result)
//OUTPUT: 20

localeCompare()

The localeCompare() method compares two strings in the current locale. The locale is based on the language settings of the browser.

Returns -1 if str1 is sorted before str2
Returns 0 if the two strings are equal
Returns 1 if str1 is sorted after str2


var str1 = "ab"; 
var str2 = "cd";

var result = str1.localeCompare(str2);

console.log(result)
//OUTPUT: -1

match()

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


var str = "The rain in SPAIN stays mainly in the plain"; 

var result = str.match(/ain/g);

console.log(result)
//OUTPUT: ["ain", "ain" "ain"]

repeat()

The repeat() method returns a new string with a specified number of copies of the string it was called on.


var str = "NAMASTE."; 

var result = str.repeat(2);

console.log(result)
//OUTPUT: NAMASTE.NAMASTE.

replace()

The replace() method searches a string for a specified value, or a regular expression, and returns a new string where the specified values are replaced.


var str = "I Like Coding"; 

var result = str.replace("Like", "Love");

console.log(result)
//OUTPUT:I Love Coding

search()

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


var str = "I Like Coding"; 
 

var result = str.search("Like");

console.log(result)
//OUTPUT: 2

JavaScript string methods :

slice()

The slice() method extracts parts of a string and returns the extracted parts in a new string.


var str = "HELLO WORLD"; 

var result = str.slice(0, 5);

console.log(result)
//OUTPUT: HELLO

split()

The split() method is used to split a string into an array of substrings, and returns the new array.


var str = "HOW ARE YOU DOING TODAY?"; 

var result = str.split(" ");

console.log(result)
//OUTPUT: ["HOW", "ARE", "YOU", "DOING", "TODAY?" ]

startsWith()

The startsWith() method determines whether a string begins with the characters of a specified string.


var str = "HOW ARE YOU DOING TODAY?"; 

var result = str.startsWith("HOW");

console.log(result)
//OUTPUT: true

substr()

The substr() method extracts parts of a string, beginning at the character at the specified position, and returns the specified number of characters.


var str = "HOW ARE YOU?"; 

var result = str.substr(4,6);

console.log(result)
//OUTPUT: ARE

substring()

The substring() method extracts the characters from a string, between two specified indices, and returns the new sub string.


var str = "HOW ARE YOU DOING TODAY?"; 

var result = str.substring(4, 6);

console.log(result)
//OUTPUT: AR

toLocaleLowerCase()

The toLocaleLowerCase() method converts a string to lowercase letters, according to the host’s current locale.


var str = "Hello World!"; 

var result = str.toLocaleLowerCase();

console.log(result)
//OUTPUT: hello world!

toLocaleUpperCase()

The toLocaleUpperCase() method converts a string to uppercase letters, according to the host’s current locale.


var str = "Hello World!"; 

var result = str.toLocaleUpperCase();

console.log(result)
//OUTPUT: HELLO WORLD!

toLowerCase()

The toLowerCase() method converts a string to lowercase letters. It does not change the original string.


var str = "Hello World!"; 

var result = str.toLowerCase( );

console.log(result)
//OUTPUT: hello world!

toUpperCase()

The toUpperCase() method converts a string to uppercase letters. It does not change the original string.


var str = "Hello World!"; 

var result = str.toUpperCase( );

console.log(result)
//OUTPUT: HELLO WORLD!

trim()

The trim() method removes whitespace from both sides of a string. It does not change the original string.


var str = "        Hello World!        "; 
console.log(str);
//OUTPUT: "        Hello World!        "

var result = str.trim( );

console.log(result)
//OUTPUT: Hello World!

I hope you like this JavaScript string methods article.