The break Statement

By Stephen Bucaro

The break statement provides you with a means of exiting a loop early. The break statement is commonly used to exit a loop when a value has reached or exceeded a set limit, or when searching through an array, when you've found the data for which you were searching.

The example below increments the variable x each time through the loop. Within the loop is an if statement that tests if x is greater than 8, and if so, executes a break statement.

var x = 0;
while (x < 12)
{
  x++;
  if(x > 8) break;
}
alert("loop exited when x = " + x);

The example below searches the day array for the day name "Wednesday", and, upon finding it, executes a break statement to end the loop.

var day = new Array("Monday","Tuesday","Wednesday",
"Thursday","Friday","Saturday","Sunday");
var index = 0;
while(index < day.length)
{
  if(day[index] == "Wednesday") break;
  index++;
}
alert("Found " + day[index]);

  Remember if you code nested loops, a break statement in an inner loop will not cause program flow to also exit an outer loop.

var x = 0;
var y = 0;
while(y < 12)
{
  while (x < 3)
  {
    if(y > 3) break;
    x++;
  }
  y++;
}
alert("loop exited x = " + x + " y = " + y);

In the example above, the inner loop contains a break statement to cause it to exit when y is greater than 3, but it exits only the inner loop, the outer loop continues to increment y.

 General Web Design
 HTML Design
 Graphics Design
 CSS Quick Reference
 Easy Cascading Style Sheets
 Java Script Quick Reference
 Easy Java Script Code
 Web Design Tools
 Coding Issues
 FREE Graphics Warehouse

RSS Feed