JavaScript - The Strings Object


Advertisements


The String object lets you work with a series of characters; it wraps Javascript's string primitive data type with a number of helper methods.

As JavaScript automatically converts between string primitives and String objects, you can call any of the helper methods of the String object on a string primitive.

Syntax

Use the following syntax to create a String object −

var val = new String(string);

The String parameter is a series of characters that has been properly encoded.

String Properties

Here is a list of the properties of String object and their description.

Sr.No Property & Description
1 constructor

Returns a reference to the String function that created the object.

2 length

Returns the length of the string.

3 prototype

The prototype property allows you to add properties and methods to an object.

In the following sections, we will have a few examples to demonstrate the usage of String properties.

String Methods

Here is a list of the methods available in String object along with their description.

Sr.No Method & Description
1 charAt()

Returns the character at the specified index.

2 charCodeAt()

Returns a number indicating the Unicode value of the character at the given index.

3 concat()

Combines the text of two strings and returns a new string.

4 indexOf()

Returns the index within the calling String object of the first occurrence of the specified value, or -1 if not found.

5 lastIndexOf()

Returns the index within the calling String object of the last occurrence of the specified value, or -1 if not found.

6 localeCompare()

Returns a number indicating whether a reference string comes before or after or is the same as the given string in sort order.

7 match()

Used to match a regular expression against a string.

8 replace()

Used to find a match between a regular expression and a string, and to replace the matched substring with a new substring.

9 search()

Executes the search for a match between a regular expression and a specified string.

10 slice()

Extracts a section of a string and returns a new string.

11 split()

Splits a String object into an array of strings by separating the string into substrings.

12 substr()

Returns the characters in a string beginning at the specified location through the specified number of characters.

13 substring()

Returns the characters in a string between two indexes into the string.

14 toLocaleLowerCase()

The characters within a string are converted to lower case while respecting the current locale.

15 toLocaleUpperCase()

The characters within a string are converted to upper case while respecting the current locale.

16 toLowerCase()

Returns the calling string value converted to lower case.

17 toString()

Returns a string representing the specified object.

18 toUpperCase()

Returns the calling string value converted to uppercase.

19 valueOf()

Returns the primitive value of the specified object.

String HTML Wrappers

Here is a list of the methods that return a copy of the string wrapped inside an appropriate HTML tag.

Sr.No Method & Description
1 anchor()

Creates an HTML anchor that is used as a hypertext target.

2 big()

Creates a string to be displayed in a big font as if it were in a <big> tag.

3 blink()

Creates a string to blink as if it were in a <blink> tag.

4 bold()

Creates a string to be displayed as bold as if it were in a <b> tag.

5 fixed()

Causes a string to be displayed in fixed-pitch font as if it were in a <tt> tag

6 fontcolor()

Causes a string to be displayed in the specified color as if it were in a <font color="color"> tag.

7 fontsize()

Causes a string to be displayed in the specified font size as if it were in a <font size="size"> tag.

8 italics()

Causes a string to be italic, as if it were in an <i> tag.

9 link()

Creates an HTML hypertext link that requests another URL.

10 small()

Causes a string to be displayed in a small font, as if it were in a <small> tag.

11 strike()

Causes a string to be displayed as struck-out text, as if it were in a <strike> tag.

12 sub()

Causes a string to be displayed as a subscript, as if it were in a <sub> tag

13 sup()

Causes a string to be displayed as a superscript, as if it were in a <sup> tag

In the following sections, we will have a few examples to demonstrate the usage of String methods.



Advertisements