With statements in JS

1. Syntax for the WITH statement

With (expression) {    statement;}

　　

　　

2. With statement: The variable scope in statement is added to expression.

Query the order of variables in the WITH statement:

(1) Whether it is a local variable in the WITH statement if it is not (2)

(2) Whether it is a variable in expression, if not (3)

(3) Find a higher scope range.

3. Example

var foo = 1;var bar = {Foo:2}with (bar) {alert (foo), foo = 3;alert (foo), var foo = 4;alert (foo)}alert (Bar.foo); alert (foo); if (true) {foo = 5;} Alert (foo);

　　

Each of these alert prints is: 2, 3,4,4,1, 5.

With statements in JS