coding-questions.md

Coding Questions:

Question: What is the value of foo?

var foo = 10 + '20';

Answer:

Output: "1020"

Question: What will be the output of the code below?

console.log(0.1 + 0.2 == 0.3);

Answer:

Output: false

Question: How would you make this work?

add(2, 5); // 7
add(2)(5); // 7

Answer:

var add = function(x) {
  return function(y) {
    return x + y;
  }
}; // This will make add (2)(5) return 7, based on closures concept in JS

Question: What value is returned from the following statement?

"i'm a lasagna hog".split("").reverse().join("");

Answer:

Splits and reverses the string to "goh angasal a m'i"

Question: What is the value of window.foo?

( window.foo || ( window.foo = "bar" ) );

Answer:

window.foo will be equal to "bar"

Question: What is the outcome of the two alerts below?

var foo = "Hello";
(function() {
  var bar = " World";
  alert(foo + bar);
})();
alert(foo + bar);

Answer:

Function will be immediately executed and give an alert "Hello World".
The call to the function will fail saying, variable bar is undefined

Question: What is the value of foo.length?

var foo = [];
foo.push(1);
foo.push(2);

Answer:

Output: 2

Question: What is the value of foo.x?

var foo = {n: 1};
var bar = foo;
foo.x = foo = {n: 2};

Answer:

Output: undefined

Question: What does the following code print?

console.log('one');
setTimeout(function() {
  console.log('two');
}, 0);
console.log('three');

Answer:

Output: "one" , and then "three" and then "two" will be printed. Even though 
the timeout is 0 seconds, the setTimeout function call will push it to JS call
stack and execute it after all other statements are executed

Question: What is the difference between these four promises?

doSomething().then(function () {
  return doSomethingElse();
});

doSomething().then(function () {
  doSomethingElse();
});

doSomething().then(doSomethingElse());

doSomething().then(doSomethingElse);