Which objects are referenced javascript

In JavaScript, reference is a very important concept. An object being referenced means that a variable stores a reference to an object, which means that the variable points to the object. This reference can be shared by multiple variables, allowing these variables to access the object.

It is very common for an object to be referenced by multiple variables. In this case, multiple variables share the same object, and any modification to this object will affect these variables at the same time. It should be noted that a variable in JavaScript is actually just a "label" pointing to an object, so multiple variables referencing the same object will cause only one copy of the object in memory. This avoids wasting memory and ensures that the state of the object is consistent across multiple places.

There are many specific forms of object references in JavaScript. Here are some common situations:

1. Object attribute references

In JavaScript , a property of an object can be another object. When a property of an object refers to another object, the object can be referenced by multiple variables. For example:

var obj1 = {
  name: 'Tom'
};

var obj2 = {
  age: 20,
  info: obj1
};

var obj3 = obj2.info;

In this example, obj1 has only one variable obj2 referenced, while obj2 has two variables obj3 and obj2.info references.

2. Function return value reference

In JavaScript, a function can return any type of value, including objects. When a function returns an object, the object can be referenced by multiple variables. For example:

function createObj() {
  return {name: 'Tom'};
}

var obj1 = createObj();
var obj2 = createObj();

In this example, the object returned by the createObj function is referenced by two variables obj1 and obj2.

3. Passing references through function parameters

When an object is passed as a parameter to a function, the object can be referenced by multiple variables. For example:

function updateInfo(obj) {
  obj.age = 20;
}

var obj1 = {
  name: 'Tom'
};

updateInfo(obj1);

var obj2 = obj1;

In this example, the obj1 object is referenced by the function updateInfo and the variable obj2.

The above are common situations where objects are referenced. It should be noted that in JavaScript, object references are a very complicated matter. Understanding these references will help us better understand and use JavaScript.

The above is the detailed content of Which objects are referenced javascript. For more information, please follow other related articles on the PHP Chinese website!