In Splits - JavaScript

The String object also comes with a split() method, which can be used to decompose a single string into separate units on the basis of a particular separator value; these units are then placed into an array for further processing. Consider the following example, which demonstrates:


<script language="Javascript">
 
// set string
var friends = "Joey, Rachel, Monica, Chandler, Ross, 
Phoebe";
 
// split into array using commas
var arr = friends.split(", ");
 
// iterate through array and print each value
for (x=0; x<arr.length; 
x++)
{
 alert("Hiya, " + arr[x]);
}
 
</script>



Up until JavaScript 1.1, you could only use string values as separators. JavaScript 1.2 changed all that; now, you can even split a string on the basis of a regular expression.

To understand this better, consider the following string, which illustrates a common problem: unequal whitespace between separated values:


Neo| Trinity   |Morpheus    |  
Smith|  Tank



Here, the | character is used to separate the various names. However, the space between the various | is unequal - which means that before you can use the individual elements of the string, you will need to trim the additional space around them. Splitting by using a regular expression as the separator is an elegant solution to the problem - as you can see from the updated listing below:


<script language="JavaScript">

// define string
var str = "Neo| Trinity   
|Morpheus    |  Smith|  Tank";
 
// define pattern
var pattern = /s*|s*/;
 
// split the string using the regular expression as the separator
result = 
str.split(pattern);
 
// iterate over result array
for(i = 0; i < result.length; i++) 
{
 alert("Character #" + (i+1) + ": " + result[i]);
}
 
</script>



The output of the call to split() above will be an array containing the names, without any leading or trailing spaces.