JavaScript String Object

The String object is used to manipulate a sequence of characters.

JavaScript Strings

A string is used to store a series of characters like "John Doe".

A string can be enclosed in single or double quotes:

Example

You can access any character in a string by using its position (index):

Example

String indexes start from zero, so the first character is at [0], the second character is at [1], and so on.

You can use quotes inside a string, as shown in the following example:

Example

var answer = "It's alright";
var answer = "He is called 'Johnny'";
var answer = 'He is called "Johnny"';

Alternatively, you can use the escape character () to include quotes in a string:

Example

var answer = 'It\'s alright';
var answer = "He is called \"Johnny\"";

String

The String object uses the length property to calculate the length of a string:

Example

Finding a String in a String

The indexOf() method is used to locate the first occurrence of a specified character in a string:

Example

If the character is not found, the function returns -1.

The lastIndexOf() method starts searching from the end of the string.

Content Matching

The match() function is used to find a specific character in a string and returns it if found.

Example

Replacing Content

The replace() method is used to replace some characters with others in a string.

Example

Converting to Upper and Lower Case

Strings are converted to upper and lower case using the functions toUpperCase() and toLowerCase():

Example

Converting a String to an Array

A string is converted to an array using the split() function:

Example

Special Characters

In JavaScript, special symbols such as apostrophes and quotes can be inserted using a backslash ().

Consider the following JavaScript code:

In JavaScript, strings start and end with single or double quotes. This means the string will be cut off as: We are the so-called

To solve this issue, use a backslash to escape the quotes:

JavaScript will output the correct text string: We are the so-called "Vikings" from the north.

The following table lists other special characters that can be escaped using a backslash:

String Properties and Methods

Properties:

• length
• prototype
• constructor

Methods:

• charAt()
• charCodeAt()
• concat()
• fromCharCode()
• indexOf()
• lastIndexOf()
• match()
• replace()
• search()
• slice()
• split()
• substr()
• substring()
• toLowerCase()
• toUpperCase()
• valueOf()

For more methods and properties, refer to: JavaScript String Object