The do/while Loop
By Stephen Bucaro
A loop structure allows you execute a series of statements over and over. Several
kinds of loop structures are available in Java Script, the do/while loop executes
the statements inside the curly brackets one time first before the condition
expression inside the whilebrackets are evaluated. The syntax for the do/while
loop is shown below.
An example of a do/while loop is shown below.
var price = 10.00;
price -= 1.00;
while(price > 5.00);
alert("The final price is: " + price);
The do/while loop is similar to the while loop except that the
while loop evaluates the test condition first before executing the statements,
but the do/while executes the statements first, then evaluates the test condition.
In the example above, the variable price is initialized to 10.00. The statements
inside the curly brackets are executed; 1.00 is subtracted from price. The Condition
expression inside the while brackets tests the value of price to see if it's greater
If the value of price is greater than 5.00, the statements inside the curly
brackets are executed again; another 1.00 is subtracted from price. The Condition
expression inside the while brackets tests the value of price to see if it's greater than 5.00.
After the statements inside the curly brackets are executed five times, the
value of price is no longer greater than 5.00. The result of the condition
expression evaluation becomes false, the do/while loop terminates.
program flow continues with the next statement following the while loop
structure, which creates a message box displaying the final value of price (5.00).
More Java Script Code:
• Java Script Number Object
• The for Loop
• Java Script Trigonometric Methods
• Format a Number as Currency
• Use Escape to Replace Dangerous Characters
• The while Loop
• Window onload Event
• Using the Java Script eval() Function
• Get Webpage File Date and File Size
• Java Script Data Types