循环使用对象中的数组

Question

function Person(name,age){ // Our Person constructor
  this.name = name ;
  this.age = age ;

var family = new Array(); // Now we can make an array of people
family [1] = new Person("alice",40);
family [2] = new Person("bob",42);
family [3] = new Person("michelle",8);
family [4] = new Person("timmy",6);

for ( var i = 0; i < family.length; i++) {
    console.log(family[i].name);
}
}

I need help with the error i am getting here . In this task i needed to create a for-loop that loops through the family array and prints out the name property for each family member in order of creation.

Answer 1

Try to close the curly brace of constructor properly,

  function Person(name,age){ // Our Person constructor
    this.name = name ;
    this.age = age ;
  }
//^------ close it here.
var family = new Array(); // Now we can make an array of people
family [1] = new Person("alice",40);
family [2] = new Person("bob",42);
family [3] = new Person("michelle",8);
family [4] = new Person("timmy",6);

for ( var i = 0; i < family.length; i++) {
    console.log(family[i].name);
}

You are not closing the bracket properly, As a result, whenever you are creating an object, the constructor is getting called, again you are creating an object inside of it and so on. So maximum call stack size exceeded. And error got raised.

As a side note, your array will look like, [undefined x 1, obj, obj .. n] since you are ignoring the zeroth index of it. So its better to use push, family.push(new Person("alice", 40));

Answer 2

function Person(name, age) { // Our Person constructor
    this.name = name;
    this.age = age;
} // <--- "}" must be here

var family = new Array(); // Now we can make an array of people
family[1] = new Person("alice", 40);
family[2] = new Person("bob", 42);
family[3] = new Person("michelle", 8);
family[4] = new Person("timmy", 6);

for (var i = 0; i < family.length; i++) {
    console.log(family[i].name);
}