Javascript / AngularJs-如何用另一个数组中的对象填充数组？

Question

Something I'm trying to do in an angularjs app that I'm making. I have a large array of the cast of a movie including directors, producers, film crew etc. and I want to make a new array of just the director(s).

I don't know how to fill a new array with specific objects form another array. Here's a quick simple example of what I mean:

this.products = [
  {name: "apple", category: "fruit"}, 
  {name: "iPhone", category: "tech"}, 
  {name: "banana", category: "fruit"}
];

this.fruits = [];

for(i = 0; i < products.length; i++) {
  if (products.category[i] == "fruit") {
    /*code to add object to fruits array*/
 }
}

Please help! Thank you!

Answer 1

try this:

for(i = 0; i < products.length; i++) {
    if (products[i].category == "fruit") {
        fruits.push(products[i].name)
    }
}

Answer 2

Try with this code this may do helpful for you

this.products = [
    {name: "apple", category: "fruit"}, 
    {name: "iPhone", category: "tech"}, 
    {name: "banana", category: "fruit"}
];

this.fruits = [];

for(i = 0; i < products.length; i++) {
    if (products[i].category === "fruit") {
        /*code to add object to fruits array*/

        fruits.push(products[i].name);
    }
}

console.log(fruits);

Answer 3

Use the filter API:

this.fruits = this.products.filter(function(product) {
                  return product.category == 'fruits';
              });

Answer 4

You can do this as follows:

this.fruits = this.products.filter(p => p.category == "fruit").map(p => p.name);

The .filter() method takes only the objects with the right category. Then .map() goes through this result, and replaces the objects by the name property value only, so that the final result is ["apple", "banana"] .

If you want the objects as a whole, then of course you leave out the .map() part.

Demo:

 new (function () { this.products = [ {name: "apple", category: "fruit"}, {name: "iPhone", category: "tech"}, {name: "banana", category: "fruit"} ]; this.fruits = this.products.filter(p => p.category == "fruit").map(p => p.name); document.write(this.fruits); });