Array.unobserve()

The Array.unobserve() method is used to remove observers set by Array.observe().

Syntax

Array.unobserve(arr, callback)

Parameters

arr

The array to stop observing.

callback

The reference to the observer to stop calling each time changes are made on the array arr.

Description

Array.unobserve() should be called after Array.observe() in order to remove an observer from an array.

The callback should be a reference to a function and not an anonymous function, because this reference will be used to unset the previous observer. It's useless to call Array.unobserve() with an anonymous function as callback, it will not remove any observer.

Examples

Unobserving an array

var arr = [1, 2, 3];

var observer = function(changes) {
  console.log(changes);
}

Array.observe(arr, observer);
​
arr.push(4);
// [{type: "splice", object: <arr>, index: 3, removed:[], addedCount: 1}]

Array.unobserve(arr, observer);

arr.pop();
// The callback wasn't called

Using an anonymous function

var persons = ['Khalid', 'Ahmed', 'Mohammed'];

Array.observe(persons, function (changes) {
  console.log(changes);
});

persons.shift(); 
// [{type: "splice", object: <arr>, index: 0, removed: [ "Khalid" ], addedCount: 0 }]

Array.unobserve(persons, function (changes) {
  console.log(changes);
});

persons.push('Abdullah');
// [{type: "splice", object: <arr>, index: 2, removed: [], addedCount: 1 }]
// The callback will always be called

Browser compatibility

See also

• Array.observe()
• Object.observe()
• Object.unobserve()