Trulia Phone Interview

PHP

1) Difference between interface and abstract class. Write code to show example of each. Can a class derive from abstract class and implement an interface as well? (Yes)

2) Write a function to test a palindrome.

Javascript :
1) What is the difference between
x = 1;
var x = 1;
window.x = 1;

2) Write a function to add an array of numbers using the arguments variable

var data = [1,2,3,4];
console.log(sum(data));

function sum() {
   var myData = arguments[0];
   return myData.reduce(function (acc, num) { acc += num; return acc});
}

3) write a function to implement mult(4)(5)

function mult(x) {
   return function(y) {
       return x*y;
   }
}

var ans = mult(4)(5);

Still concise :

function mult(num1) {
  return num2 => num1 * num2;
}

console.log(mult(4)(5));

4) Write a function to output alert(1), alert(2) every 1 second till 5 times
Similar to question asked in Ten-X interview.

5) write a function to put spaces in a string “Hello World” ==> “H e l l o W o r l d”.

var spacify = function (str) {
    return str.split('').join(' ');
};

console.log(spacify("Hello"));

Is it possible to write a function spacify like “hello world”.spacify()

String.prototype.spacify = String.prototype.spacify || function() {
  return this.split('').join(' ');
};

console.log("Hello".spacify());