Possible Interview Questions

difference.js

// Remove elements of second array from the first array

// Ex. 1 JavaScript Filter (no IE 8 support)
var arr1 = ['A', 'B', 'C', 'D', 'E', 'F'],
    arr2 = ['C', 'E', 'F'],
    filteredArray;
    
filteredArray = arr1.filter(function(e, i) {
    return !(arr2.indexOf(e) > -1);
});

console.log('difference', filteredArray);

// Ex. 2 Basic for loops (modifies original array)
var arr3 = ['A', 'B', 'C', 'D', 'E', 'F'],
    arr4 = ['C', 'E', 'F'];

for (var i = 0; i < arr4.length; i += 1) {
    for (var j = 0; j < arr3.length; j += 1) {
        if (arr4[i] === arr3[j]) {
            arr3.splice(j, 1);
        }
    }
}

console.log('difference', arr3);

// Ex. 3 use Underscore/LoDash _.difference method
var arr5 = ['A', 'B', 'C', 'D', 'E', 'F'],
    arr6 = ['C', 'E', 'F'],
    difference;

difference = _.difference(arr5, arr6);

console.log('difference', difference);

fizzBuzz.js

for (var i = 1; i <= 100; i++) {
    if (i % 15 == 0) {
      console.log("FizzBuzz");
    } else if (i % 3 == 0) {
        console.log("Fizz");
    } else if (i % 5 == 0) {
        console.log("Buzz");
    } else {
      console.log(i);
    }
}

minMax.js

// Find the min/max value in an array

// Ex. 1 Math Object
var myArray,
    max,
    min;

myArray = [1, 2, 3, 4, 5];

max = Math.max.apply(null, myArray);
min = Math.min.apply(null, myArray);

console.log('max', max);
console.log('min', min);

// Ex. 2 Sort
var myArray1,
    max1,
    min1;

myArray1 = [2, 4, 5, 3, 1];

function sortNum(a, b) {
    return a - b;
}

myArray1.sort(sortNum);

max1 = myArray1[myArray.length - 1];
min1 = myArray1[0];

console.log('max', max1);
console.log('min', min1);

// Ex. 3 Use Underscore/LoDash min/max methods
var myArray2,
    max,
    min;

myArray2 = [2, 4, 5, 3, 1];

console.log('max', _.max(myArray2));
console.log('min', _.min(myArray2));

variableSwap.js

// Swap the values of two variables

// Ex. 1 Temp variable
var a = 1,
    b = 2,
    tmp;

tmp = a;
a = b;
b = tmp;

console.log('a', a);
console.log('b', b);

// Ex. 2 XOR operator
var c = 1,
    d = 2;

c = c ^ d;
d = c ^ d;
c = c ^ d;

console.log('c', c);
console.log('d', d);

// Ex. 3 ECMAScript 6
var e = 1,
    f = 2;

[e, f] = [f, e];

console.log('e', e);
console.log('f', f);