1.1 KiB
1.1 KiB
title |
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Iterate Through the Keys of an Object with a for...in Statement |
Iterate Through the Keys of an Object with a for...in Statement
Method:
- Note:
dot-notation
will cause errors in this challenge. [square-bracket]
notation must be used to call a variable property name.- The following code will not work.
Example 1:
for (let user in obj) {
if(obj.user.online === true) {
//code
}
}
- Example 2 demonstrates how using
[square-bracket]
notation the code will be executed.
Example 2:
for (let user in obj) {
if(obj[user]online === true) {
//code
}
}
Solution:
let users = {
Alan: {
age: 27,
online: false
},
Jeff: {
age: 32,
online: true
},
Sarah: {
age: 48,
online: false
},
Ryan: {
age: 19,
online: true
}
};
function countOnline(obj) {
// change code below this line
let result = 0;
for (let user in obj) {
if(obj[user].online === true) {
result++;
}
}
return result;
// change code above this line
}
console.log(countOnline(users));