January 25, 2001 - Extracting DOM Substrings | WebReference

January 25, 2001 - Extracting DOM Substrings

Yehuda Shiran January 25, 2001
Extracting DOM Substrings
Tips: January 2001

Yehuda Shiran, Ph.D.
Doc JavaScript

Netscape 6 is richer in functionality than Internet Explorer 5, as far as text manipulation is concerned. The substringData() method is one example. Operating on text nodes, it extracts a substring from the text node data. You can specify the offset of the substring and its length. Here is its syntax: 

strValue = textObj.substringData(offset, count);

where:

offset is a long integer value indicating the offset of the substring, in characters, from the beginning of the string.
    • count is a long integer value indicating the number of characters to retrieve, starting from the specified offset.

    Let's create a text node at the document level. We put the following line in the header of this tip:

    txtObj = document.createTextNode("Doc JavaScript");

    Now, let's extract a substring that starts at offset 4 and of length 5. Click this button to get the answer in Netscape 6. Click in Internet Explorer 5.x and get an error message:

    Here is the definition of this button:

    <FORM>
<INPUT TYPE="button" VALUE="Extract a Substring" onClick="javascript:alert(txtObj.substringData(4,5))">
</FORM>