Learn
Objects
Looping Through Objects

Loops are programming tools that repeat a block of code until a condition is met. We learned how to iterate through arrays using their numerical indexing, but the key-value pairs in objects aren’t ordered! JavaScript has given us alternative solution for iterating through objects with the for...in syntax .

for...in will execute a given block of code for each property in an object.

let spaceship = { crew: { captain: { name: 'Lily', degree: 'Computer Engineering', cheerTeam() { console.log('You got this!') } }, 'chief officer': { name: 'Dan', degree: 'Aerospace Engineering', agree() { console.log('I agree, captain!') } }, medic: { name: 'Clementine', degree: 'Physics', announce() { console.log(`Jets on!`) } }, translator: { name: 'Shauna', degree: 'Conservation Science', powerFuel() { console.log('The tank is full!') } } } }; // for...in for (let crewMember in spaceship.crew) { console.log(`${crewMember}: ${spaceship.crew[crewMember].name}`); }

Our for...in will iterate through each element of the spaceship.crew object. In each iteration, the variable crewMember is set to one of spaceship.crew‘s keys, enabling us to log a list of crew members’ role and name.

Instructions

1.

Using for...in, iterate through the spaceship.crew object in the code editor and console.log() a list of crew roles and names in the following format: '[crew member's role]: [crew member's name]', e.g.,'chief officer: Dan'.

2.

Using for...in, iterate through the spaceship.crew object in the code editor and console.log() a list of crew names and degrees in the following format: '[crew member's name]: [crew member's degree]', i.e.,'Lily: Computer Engineering'.

Folder Icon

Take this course for free

Already have an account?