Practice working with JavaScript objects using the following problems. The solutions are hidden below.
/*
Javascript Objects Exercise
*/
/*
1. Write a method that verifies whether an argument is a plain object, not an array or null
It should return true for an object, and false otherwise. ({ a: 1 }) => true, ([1, 2, 3]) => false
*/
const data = { a: 1 };
const data = [1, 2, 3];
console.log(checkObject(data));
function checkObject(element) {
//put your code here
}
/*
2. Change the value of "room" to be correct in the courseInfo object
*/
let courseInfo = {
name: 'HCDE 438',
instructor: 'Hannah Twigg-Smith',
room: 'SIEG 128'
};
//put your code here
console.log(courseInfo);
/*
3. Add a new key/value pair to the courseInfo object
*/
//put your code here
console.log(courseInfo);
/*
4. Iterate over the courseInfo object and print the key/value pairs
*/
//put your code here
/*
5. Delete a key/value pair in the courseInfo object
*/
//put your code here
console.log(courseInfo);
/*
6. Iterate through an array of objects and print each object (in this case the objects are coordinate positions)
*/
let positions = [
{x: 200, y: 100},
{x: 200, y: 200},
{x: 200, y: 300}
];// 1. Write a method that verifies whether an argument is a plain object, not an array or null
function checkObject(element) {
return typeof element === 'object' && !Array.isArray(element) && element !== null;
}
// 2. Update a value in the courseInfo object
courseInfo.room = 'SIEG 329'; // or courseInfo['room'] = 'SIEG 329'
// 3. Add a key/value pair to the courseInfo object
courseInfo.quarter = 'Winter'; // or courseInfo['quarter'] = 'Winter'
// 4. Iterate over the courseInfo object and print the key/value pairs
// Starting from ECMAScript 2017 we can use the Object.entries method.
// Object.entries() method returns an array of key-value pairs which helps us use the forEach() method -- a way of iterating over elements of an array.
Object.entries(courseInfo).forEach(([key, value]) => {
console.log(`${key}: ${value}`);
});
// you can also do this using a for loop
for (var key in courseInfo) {
console.log(`${key}: ${courseInfo[key]}`);
}
// 5. Delete a key/value pair in the courseInfo object
delete courseInfo.room;
// 6. Iterate through an array of objects and print each object
for (var i = 0; i < positions.length; i++) {
var position = positions[i];
console.log(`${position.x}: ${position.y}`);
}