|Home | Tutorial | Classes | Functions | QSA Workbench | Language | Qt API | QSA Articles | Qt Script for Applications | ![]() |
[Prev: Control Statements] [Home] [Next: case]
label: for ( var i = 0; i < limit; i++ ) { if ( condition ) { break label; } } switch ( expression ) { case 1: Statements1; break; default: DefaultStatements; break; }
This keyword is used in for loops, do loops, while loops and switch statements. When a break statement is encountered in a loop, control is passed to the statement following the end of the inner-most loop that contains the break statement; unless the break statement is followed by the name of a label, in which case control passes to the statement governed by the label.
A break statement is usually placed at the end of each case in a switch statement to prevent the interpreter "falling through" to the next case. When the interpreter encounters a break statement, it passes control to the statement that follows the inner-most enclosing switch statement. If every case has a corresponding break, then at most one case's statements will be executed. If the break statement is followed by a label name (label) then when the break is encountered, control will pass to the statement marked with that label; this is useful, for example, for breaking out of deeply nested loops.
Example:
red: for ( x = 0; x < object.width; x++ ) { for ( y = 0; y < object.height; y++ ) { if ( color[x][y] == 0xFF0000 ) { break red; } } }
See switch for another example. See also do, while, for and break.
[Prev: Control Statements] [Home] [Next: case]
Copyright © 2001-2006 Trolltech | Trademarks | QSA version 1.1.5
|