| Applying science to business management |
   
while
The while statement is used to create an execution
loop. More specifically, while will repeatedly evaluate a
statement or statement block until some condition is met. The while
statement has the format
while( expression )
statement
While first evaluates expression, and if it is true,
executes statement. While then repeats this process
until expression becomes false. If expression
is false when it is first evaluated, statement is
never executed.
The following example adds the square of all integers from 1
to 10 (inclusive):
var total=0,n=1;
while(n<=10) {
total+=n*n;
n++;
}
In the first evaluation of the expression n<=10, n is equal to 1; so,
the expression is true. This means the statement block
following while should be executed. The first statement in
the block adds the value of n*n
to total. The second statement adds one to n. After
executing the block, the expression n<=10
is evaluated again. This time, n is equal to 2; so, the
expression is still true. This process continues until n
is equal to 11. At this point, the conditional expression will be
false and execution of the while loop ends.
|
