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The break and continue statements

Labeled statements

It is possible to label statements for later use with the following syntax:

label

statement

For example:

start: var iCount = 10;

In this example, the label

start

can later be referenced by using the

break

continue

statements.

The break and continue statements

The

break

and

continue

statements provide stricter control over the execution of code in a loop. The

break

statement exits the loop immediately, preventing any further repetition of the code while the

continue

statement exits the current repetition. It does, however, allow further repetition based on

the control expression. For example:

var iNum = 0;

for (var i=1; i < 10; i++) {

if (i % 5 == 0) {

break;

}

iNum++;

}

alert(iNum); //outputs “4”

In the previous code, the

for

loop is to iterate the variable

from 1 to 10. In the body of loop, an

statement checks to see if the value of

is evenly divisible by 5 (using the modulus operator). If so, the

break

statement is executed and the alert displays

“4”

, indicating the number of times the loop has

been executed before exiting. If this example is updated to use

continue

instead of

break

, a different

outcome occurs:

var iNum = 0;

for (var i=1; i < 10; i++) {

if (i % 5 == 0) {

continue;

}

iNum++;

}

alert(iNum); //outputs “8”

Here, the alert displays

“8”

, the number of times the loop has been executed. The total number of times

that the loop can possibly be executed is 9, but when

reaches a value of

, the

continue

statement is

executed, causing the loop to skip the expression

iNum++

and return to the top.

Chapter 2

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