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Object.freeze

suggest change

Object.freeze makes an object immutable by preventing the addition of new properties, the removal of existing properties, and the modification of the enumerability, configurability, and writability of existing properties. It also prevents the value of existing properties from being changed. However, it does not work recursively which means that child objects are not automatically frozen and are subject to change.

The operations following the freeze will fail silently unless the code is running in strict mode. If the code is in strict mode, a TypeError will be thrown. 

var obj = {
  foo: 'foo',
  bar: [1, 2, 3],
  baz: {
    foo: 'nested-foo'
  }
};

Object.freeze(obj);

// Cannot add new properties
obj.newProperty = true;

// Cannot modify existing values or their descriptors
obj.foo = 'not foo';
Object.defineProperty(obj, 'foo', {
    writable: true
});

// Cannot delete existing properties
delete obj.foo;

// Nested objects are not frozen
obj.bar.push(4);
obj.baz.foo = 'new foo';
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Objects:
* Syntax
* Parameters
* Shallow cloning
* Object.freeze
* Object cloning
* Object properties iteration
* Object.assign
* Object rest / spread (...)
* Accessor properties get and set
* Convert objects values to array
* Dynamic variable property names
* Arrays are Objects
* Object.defineProperty
* Object.seal
* Retrieving properties from an object
* Object.keys
* Descriptors and Named Properties
* Object.getOwnPropertyDescriptor
* Lock property description
* Non enumerable property
* Read-only property
* Creating an iterable object
* Properties with special characters or reserved words
* Iterating entries with Object.entries
* Object.values
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105 Contributors