Exlained Answers of JavaScript Web Quiz by David Shariff
Try the most advance and complex JavaScript Quiz implemented by David Shariff
Compare two arrays and find difference between them?
<script type="text/javascript">
var array1 = [1, 2, 3, 4, 5, 6];
var array2 = [1, 2, 3, 4, 5, 6, 7, 8, 9];
var result = [];
/***********Method 1************/
var count = 0;
$.grep(array2, function (index) {
console.log(index);
if ($.inArray(index, array1) == -1)
result.push(index);
count++;
});
console.log(" the difference is " + result);
/************Method 2**************/
var len = array2.length;
for (var i = 0; i <= len - 1; i++) {
if (array1.indexOf(array2[i]) == -1) {
result.push(array2[i]);
}
}
console.log(" the difference is " + result);
/************Method 3**************/
var diff = $(array2).not(array1).get();
alert(diff);
</script>
Find the second largest element from an array in javascript?
function findSecondLargest(arr) {
// Sort the array in descending order
arr.sort((a, b) => b - a);
// If the array has less than two elements, return undefined
if (arr.length < 2) {
return undefined;
}
// Return the second element
return arr[1];
}
// Example usage
const array = [10, 5, 20, 15];
const secondLargest = findSecondLargest(array);
console.log('Second largest element:', secondLargest); // Output: 15
var secondMax = function (arr) {
var max = Math.max.apply(null, arr); // get the max of the array
arr.splice(arr.indexOf(max), 1); // remove max from the array
return Math.max.apply(null, arr); // get the 2nd max
};
var arr = [20, 120, 111, 215, 54, 78]; // use int arrays
var max2 = secondMax(arr);
alert(max2);
Find smallest element from array without using any built-in function
// Find smallest element from array without using any built-in function
var arr = [7,2,4,3,1,6,5,8];
var minEle = arr[0];
for(var i=1; i<arr.length; i++){
if(arr[i] < minEle ){
minEle = arr[i];
}
}
alert(minEle);
Create a for loop that iterates up to 100 while outputting "fizz" at multiples of 3, "buzz" at multiples of 5 and "fizzbuzz" at multiples of 3 and 5
<script type="text/javascript">
for (var i = 1; i <= 100; i++) {
if (i % 3 === 0 && i % 5 === 0)
console.log(i + "== fizzbuzz");
else if (i % 3 === 0)
console.log(i + "== fizz");
else if (i % 5 === 0)
console.log(i + "== buzz");
}
</script>
List Prime Numbers between 1 to 100 in JavaScript
for (var p = 2; p <= 100; p++) {
var isPrime = true;
// Check divisibility from 2 to square root of p
for (var i = 2; i <= Math.sqrt(p); i++) {
if (p % i === 0) {
isPrime = false;
break; // Exit the loop if p is not prime
}
}
// If isPrime is still true, p is a prime number
if (isPrime) {
console.log(p);
}
}
- Iterate through each number p from 2 to 100.
- For each p, we set a flag isPrime to true initially, assuming it's prime.
- We then check divisibility of p with all numbers from 2 to the square root of p.
- If p is divisible by any number in this range, we set isPrime to false and break out of the loop.
- If isPrime is still true after checking all numbers, p is a prime number, and we log it to the console.
List Fibbonaci upto 100 in JavaScript
<script type="text/javascript">
//The Fibonacci sequence is a series where the next term is the sum of pervious two terms.
//The first two terms of the Fibonacci sequence is 0 followed by 1.
var t1 = 0, t2 = 1, nextTerm = 0;
console.log(t1); // print 0 as it is
console.log(t2); // print 1 as it is
for (var i = 0; i <= 100; i++) {
nextTerm = t1 + t2;
t1 = t2;
t2 = nextTerm;
console.log(nextTerm);
}
</script>
How to add something in the beginning and end of an array
var array = ['Java','PHP','SQL','HTML'];
// add "Angular" in the beginning
array.unshift('Angular');
// add "React" in the end
array.push('React');
alert(array);
// OR ES6 Way using spread operator
array = ["Angular",...array,"React"];
alert(array);
How to find duplicate elements from an Array
//var myArr = [ 'x','y','a','x','b','b','a','c','b','k','b' ];
var myArr = [ 6, 4, 5, 5, 5, 2, 1, 3, 1, 1, 2, 1, 3, 4, 7 ];
// you must need to sort the array first
var myArrSorted = myArr.sort();
// in filter function
// 1st parameter is each element from an array
// 2nd parameter is index of each element
// 3rd parameters is an array itself
// so we need to check if each element with its next element and
// return only if element is not duplicate
var result = myArrSorted.filter( function(element,index,arrayitself){
if(element !== arrayitself[index+1]){
return element;
}
});
console.log(result);
Remove adjacent duplicate characters from string
// remove adjacent duplicate characters from string
// ex:
// input: AAABBCDDDAAD
// output: ABCDAD
let string = "AAABBCDDDAAD";
let len = string.length;
let newStr = "";
for(let i=1; i<len+1; i++){
if(string[i] != string[i-1]){
newStr += string[i-1];
}
}
console.log(newStr)
Sort an Array without using any built-in JavaScript function.
let arr = [5,2,4,10,3,1,5];
//let arr = ['d','a','c','b','e'];
let sortArr = function(arr){
flag = true;
while(flag){
flag = false;
for(let i=0;i<arr.length;i++){
if(arr[i] > arr[i+1]){
let temp = arr[i];
arr[i] = arr[i+1];
arr[i+1] = temp;
flag = true;
}
}
}
return arr;
}
sortArr(arr);