Look to the following table for JavaScript control structures you can use in your program code to add branching and looping behavior to your JavaScript programs.

Element Description
if (condition){
// content
} else {
// more content
} // end if
Executes content only if condition is true.
Optional else clause occurs if condition is false.
switch (expression)
case: value;
//code
break;
default:
//code
}
Compares expression against one or more values. If expression is equal to value, runs corresponding code.
Default clause catches any uncaught values.
for(i = 0; i < count; i++)
//code
} // end for
Repeats code i times.
While (condition){
//code
} // end while
Repeats code as long as condition is true.
Function fnName(paramaters) {
//code
} // end function
Defines a function named fnName and sends it parameters. All code inside the function will execute when the function is called.