/ Published in: JavaScript
Source: controls @ howtocreate
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// ------------------------- // switch switch(myVar) { case 1: //if myVar is 1 this is executed break; case 'sample': //if myVar is 'sample' this is executed break; case false: //if myVar is false this is executed break; default: //if myVar does not satisfy any case, this is executed //break; is unnecessary here as there are no cases following this } // ------------------------- // with x = Math.round( Math.LN2 + Math.E + Math.pow( y, 4 ) ); // replace by with( Math ) { x = round( LN2 + E + pow( y, 4 ) ); } // ------------------------- // quick if var myVariable = document.getElementById ? 1 : 0; // ------------------------- // try/catch/final try { //do something that might cause an error } catch( myError ) { //if an error occurs, this code will be run //two properties will (by default) be available on the //object passed to the statement alert( myError.name + ': ' + myError.message ); } finally { //optional - this code will always be run before the //control structure ends, even if you rethrow the error //in the catch } // ------------------------- // throw try{ var myEr = new Object(); myEr.name = 'My error'; myEr.message = 'You did something I didn\'t like'; throw( myEr ); } catch( detectedError ) { alert( detectedError.name + '\n' + detectedError.message ); } // ------------------------- // break to a label (best avoided) myForLoop: for( var x = 1; x < 5; x++ ) { var y = 1; while( y < 7 ) { y++; if( y == 5 ) { break myForLoop; } document.write(y); } } // ------------------------- // continue // Will cause the program to jump to the test condition of the structure // and re-evaluate it having performed any 'do_this_each_time' // instructions. myForLoop: for( var x = 1; x < 5; x++ ) { var y = 1; while( y < 7 ) { y++; if( y == 5 ) { continue myForLoop; } document.write(y); } }
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