JS variable change lock

Question

Can you please tell me how to block a variable change in JS? can somehow undo its change.

Ajax('POST', '/Controller/path', {}, function (result) { window.test = result.test; //как заблокировать изменение этой переменной. Ведь её можно изменить через консоль. });

Do you want to block the value of a variable in javascript or do you want to block the value of one or another html attribute?

hal_tim hal_tim eleven 2 · Answer 1 · 2017-04-05T06:42:37

This can be done by declaring a variable using Object.defineProperty.

Example:

 Object.defineProperty(window, "test", { value: "Неизменяемое", writable: false, // запретить присвоение "test=" configurable: false // запретить удаление "delete test" });

Important! Without use strict write operation "silently" will not work. If use strict mode is set, then an error is additionally generated.

that's just it will not help if the debugger to save the value that is assigned to this property.

Mikl mikl 3.181 five 14 · Answer 2 · 2017-04-04T15:24:55

Well, there is no such possibility in the current standard. There are some agreements, for example, if a variable name begins with _ then its value should not be changed directly.

 _superConst = "super"; //менять можно, но делая это вам будет стыдно

But, I hope, in the near future, in the new js standard, the variable declaration as const will be available. The value of a variable declared as const physically forbidden to change.

 const _superConst = "super"; //менять не получится

You can use this feature now if you connect babel or any other js code translator that can turn es6 into es5 javaScript.

Community spirit ♦ one · Answer 3 · 2017-04-04T14:03:56

let's say you have an object named Person and you want to create a static value for it.

 function Person(){ this.name = "Peter"; }

then create a variable and equate the instance of this object

 var p1 = new Person();

source code

JS variable change lock

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