var arr1=[1,2,3,4];

var arr2=arr1;

arr2.push(5);

console.log(arr1);//和arr2一样

console.log(arr1==arr2);//true

console.log(arr1===arr2);//true

function Cat(name){

this.name=name;

}

var p1=new Cat('tom');

var p2=new Cat('tom');

console.log(p1==p2);//false

p2=p1;

console.log(p1==p2);//true

p1.name='toms';

console.log(p2.name);//toms