CATHMHAOL :: References :: JavaScript

break

Stops execution of the block and exits to the containing block.

catch

Catches thrown exceptions.

continue

Continues with the next step in the iteration.

delete

Deletes the item.

Executes a block until the specified expression evaluates to false. Note that the block will execute at least one time because the while statement is evaluated after the specified block is executed.

var i = 0;
do {
	var oCar = Cars[i]
	oCar.start();
}
while (i < Cars.length);

export

Allows a signed script to provided objects to other script.

for

Creates a loop.

for (var c = 0; c < Cars.length; c++) {
	var oCar = Cars[c];
	oCar.start();
}

if...else

Executes the specified block if the expression evaluates to true. When coding a conditional, you should always use { and } to identify the block.

if (Cars.length > 0) {
	StartCars();
} else {
	BuildCars();
}

import

Allows a script to import objects exported by a signed script. See export.

new

Creates a new object of the specified type, calling the prototype.

var oCar = new Car("Mazda", "Protege");

return

Passes control back from a function and optionally returns an object.

switch

Tests an expression against a number of specified cases and executes the specified block. If a block is not terminated by a break statement, processing will continue into the next block. You can also specify a default block to execute when all other cases are false.

switch (Cars.length) {
	case 0:
		alert("Your garage is empty!");
		break;
	case 1:
		alert("You have only one car in your garage.");
		break;
	default:
		alert("You have "+Cars.length+" cars in your garage.");
}

this

A reference to the current object.

throw

Throws the specified error. Allows a greater degree of control with a try...catch block.

try {
	if (Car.crashed) {
		throw {type: "Accident", auto: Car};
	}
} catch (er) {
	if (er.type == "Accident") {
		alert("Your car, a "+er.auto.maker+" "+er.auto.model+", was in an accident.");
	}
}

try...catch

Attempts to execute a block and catches errors.

try {
	if (Car.crashed) {
		throw {type: "Accident", auto: Car};
	}
} catch (er) {
	if (er.type == "Accident") {
		alert("Your car, a "+er.auto.maker+" "+er.auto.model+", was in an accident.");
	}
}

typeof

Returns the type of the operand.

boolean
function
number
object
string
undefined

if (typeof oCar != object) {
	alert("Oops! We've had a severe error.");
}

while

Creates a loop that executes while the expression evaluates to true.

var i = 0;
while (i < Cars.length) {
	var oCar = Cars[i];
	oCar.start();
}

with

Establishes a default object for a set of statements.

with (oCar) {
	if (crashed) {
		alert("Your car, a "+maker+" "+model+", was in an accident.");
	}
}

JavaScript Reference :: Statements