Skip to content

Instantly share code, notes, and snippets.

@rootTheLure

rootTheLure/interview-quick-check.js

Last active February 28, 2019 14:14
Show Gist options
  • Save rootTheLure/8bc261a750c61126e63b51705abff8db to your computer and use it in GitHub Desktop.
Save rootTheLure/8bc261a750c61126e63b51705abff8db to your computer and use it in GitHub Desktop.
Download ZIP
Raw
interview-quick-check.js
// 1) what is console output for every line below
typeof 5;
typeof new Number();
typeof 0;
typeof -0;
typeof null;
typeof undefined;
typeof NaN;
typeof !0+1;
typeof Object;
// 2) what is result of 2 function calls below
const karl = {
name: 'Karl',
sayYourName: () => { console.log(this.name); },
sayItAgain: function () { console.log(this.name); }
}
karl.sayYourName();
karl.sayItAgain();
// 3) what is the order of console.logs below
console.log('script start');
setTimeout(function() {
console.log('setTimeout');
}, 0);
Promise.resolve().then(function() {
console.log('promise1');
}).then(function() {
console.log('promise2');
});
console.log('script end');
// 4) What is the result of function calls below
function printThis() {
console.log(this);
}
const firstObj = { name: 'FIRST' };
const secondObj = { name: 'SECOND' };
const printFirst = printThis.bind(firstObj);
const printSecond = printFirst.bind(secondObj);
printThis();
printFirst();
printSecond();
// 5) Are this selector equal?
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Selector</title>
</head>
<body>
<div class='outer'>
<div class='inner'>
<div>
<div></div>
<div></div>
</div>
<div></div>
</div>
<div></div>
<div></div>
</div>
</body>
</html>
const length = document.querySelectorAll('.inner div div').length;
const length2 = document.querySelector('.inner').querySelectorAll('div div').length;
console.log(length === length2);
// 6) what is an output
for (var i = 0; i < 10; i++) {
setTimeout(() => {
console.log(i);
}, 0);
}
// 6.1) what is an output
var i = 0;
while(i++ < 4) {
let s = i;
setTimeout(function() {
console.log(i);
}, i * 100);
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment