js object assignment

Direct assignment: By assigning a reference to an object to another variable, they point to the same object. When one variable changes the object, the other variable also reflects this change.

const obj1 = {
    
     key: 'value' };
const obj2 = obj1;

Object Spread Operator (Spread Operator): By using the spread operator..., you can create a new object and copy all the properties of another object into the new object.

const obj1 = {
    
     key1: 'value1' };
const obj2 = {
    
     ...obj1 };

Object.assign() method: This method is used to copy the properties of one or more source objects to the target object. It can also be used to create a new object.

const obj1 = {
    
     key1: 'value1' };
const obj2 = Object.assign({
    
    }, obj1);

Manual attribute copying: By traversing the attributes of the source object, they are copied to the target object one by one.

const obj1 = {
    
     key1: 'value1' };
const obj2 = {
    
    };
for (let key in obj1) {
    
    
  if (obj1.hasOwnProperty(key)) {
    
    
    obj2[key] = obj1[key];
  }
}

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Origin blog.csdn.net/qq_44063746/article/details/130702356