JavaScript: The Definitive Guide, 5th Edition

Name

CharacterData.substringData( ): extract a substring from a Text or Comment node — DOM Level 1 Core:

Synopsis

String substringData(unsigned longoffset,
                     unsigned long count)
    throws DOMException;

Arguments

offset

The position of the first character to be returned.

count

The number of characters in the substring to be returned.

Returns

A string that consists of count characters of the Text or Comment node starting with the character at position offset.

Throws

This method may throw a DOMException with one of the following code values:

INDEX_SIZE_ERR

offset is negative or greater than the length of the Text or Comment node, or count is negative.

DOMSTRING_SIZE_ERR

The specified range of text is too long to fit into a string in the browser’s JavaScript implementation.

Description

This method extracts the substring that starts at position offset and continues for count characters from the text of a Text or Comment node. This method is useful only when the amount of text contained by the node is larger than the maximum number of characters that can fit in a string in a browser’s JavaScript implementation. In this case, a JavaScript program cannot use the data property of the Text or Comment node directly and must instead work with shorter substrings of the node’s text. This situation is unlikely to arise in practice.