(╯°□°)╯ .filter()

We use this function in JavaScript to return a new array from the items matched true from the condition passed in the function.

Example 1

const myArray = [1, 2, 3, 4];
 const newArray = myArray.filter((num) => num >= 2);

// [ 2, 3, 4 ]

We used the filter function to filter through the numbers that matched true to the condition. In this case, the condition is to return numbers equal and bigger than 2 in a new array.

Example 2

We have an array of objects with criteria. We want to return a new array containing certain criteria from the array of objects.

const dogArr = [
    {
      name: "Spike",
      age: 5,
      vaccinated: true,
      breed: "Border Terrior",
    },
    {
      name: "Rex",
      age: 8,
      vaccinated: true,
      breed: "Border Collier",
    },
    {
      name: "Boeta",
      age: 12,
      vaccinated: false,
      breed: "Labrador",
    },
    {
      name: "Ozzy",
      age: 2,
      vaccinated: true,
      breed: "German Shepard",
    },
  ];

const isVaccinated = dogArr.filter((dog) => dog.vaccinated === true);

/* [
{name: "Spike", age:5, vaccinated:true},
{name: "Rex", age:8, vaccinated:true},
{name:"Ozzy", age:2, vaccinated:true}
]*/

In this example we wanted a new array of objects of the dogs that are vaccinated. We iterated through the data and returned the data that === true by using the filter() method.