codeup-web-exercises/MapFilterReduceMiniExercise.html at master · liliwang1/codeup-web-exercises · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Map Filter Reduce Mini Exercise</title>
</head>
<body>

<script>
    "use strict";
    const dogs = [
        {
            name: 'bubbles',
            age: 10,
            isTrained: false
        },
        {
            name: 'lexie',
            age: 3,
            isTrained: true
        },
        {
            name: 'doggy',
            age: 5,
            isTrained: false
        }
    ];

    // TODO: using map, create a new array of dog names from the dogs array
    // TODO: using map, create a new array of dog ages from the dogs array
    // TODO: using map, create a new array of dog objects from the dogs array that only have name and age property values
    const nameArr = dogs.map(({ name }) => name);
    const ageArr = dogs.map(dog => dog.age);
    const objArr = dogs.map(({ name, age }) => {return {name, age}});
    const objArr1 = dogs.map(({ name, age }) => ({name, age})); // !!! on right hand side of =>, without the (), javascript will think the object is the function body within {}.
    const objArr2 = dogs.map(dog => ({name: dog.name, age: dog.age}));

    // TODO: using filter, create a new array containing only dogs younger than 10 years old
    // TODO: using filter, create a new array containing only dogs named 'lexie'
    // TODO: using filter, create a new array containing only dogs that are trained and younger than 10
    const youngDogs = dogs.filter(dog => dog.age < 10);
    const youngDogs1 = dogs.filter(({ age }) => age < 10);
    const lexieDog = dogs.filter(dog => dog.name === 'lexie');
    const lexieDog1 = dogs.filter(({ name }) => name === 'lexie');
    const trainedYoungDogs = dogs.filter(dog => dog.age < 10 && dog.isTrained === true);
    const trainedYoungDogs1 = dogs.filter(dog => dog.age < 10 && dog.isTrained);
    const trainedYoungDogs2 = dogs.filter(({ age, isTrained }) => age < 10 && isTrained === true);
    const trainedYoungDogs3 = dogs.filter(({ age, isTrained }) => age < 10 && isTrained);
</script>
</body>
</html>