Programming Articles - Page 1962 of 3366

The mostly used core modules of Node.js are −http − used to launch a simple server, send requestshttps − used to launch a ssl secured http serverpath − used to handle path based on operating systemfs − It’s a file system handling moduleos − its used for os related operationsLets build a simple http server using Node.js −Create a javascript file App.js (name it as you like) in an editor like visual studio code .App.jsconst http = require(‘http’); function reqListener(req, res){    console.log(‘Hello’); } const server = http.createServer(reqListener); server.listen(3000);ExplainationWe used const keyword instead of var or let to import a ... Read More

The JavaScript symbol.toString() returns the string representation of the specified symbol object.Following is the code for Symbol.toString() method −Example Live Demo Document    body {       font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;    }    div {       font-size: 20px;       font-weight: 500;    } JavaScript symbol.toString() method CLICK HERE Click on the above button to get the string representation for symbol    let fillEle = document.querySelector(".sample");    const symbol = Symbol.for("HELLO");    const symbol1 = Symbol.for("NEW");    const symbol2 = Symbol.for(711);    document.querySelector(".Btn").addEventListener("click", () => {       fillEle.innerHTML += symbol.toString() + "";       fillEle.innerHTML += symbol1.toString() + "";       fillEle.innerHTML += symbol2.toString() + "";    }); OutputOn clicking the “CLICK HERE” button −

Suppose there is a special square room with mirrors on each of the four walls. In each corner except the southwest corner, there are receptors. These are numbered as 0, 1, and 2. Now the square room has walls of length p, and a laser ray from the southwest corner first meets the east wall at a distance q from the 0th receptor. We have to find the number of the receptor that the ray meets first.So if p = 2, and q = 1, then the case will be like −So the output will be 2, as the ray ... Read More

Suppose we have a balanced parentheses string S, we have to compute the score of the string based on the following rule −The () has score 1AB has score A + B, where A and B are two balanced parentheses strings.(A) has score 2 * A, where A is a balanced parentheses string.So if the input is like “(()(()))”, then the output will be 6.To solve this, we will follow these steps −ans := 0, define a stack stfor i in range 0 to size of string Sif S[i] is opening parentheses, then insert -1 into stackotherwiseif top of stack ... Read More

Suppose there are N cars that are going to the same destination along a one lane road. The destination is ‘target’ miles away. Now each car i has a constant speed value speed[i] (in miles per hour), and initial position is position[i] miles towards the target along the road.A car can never pass another car ahead of it, but it can catch up to it, and drive bumper to bumper at the same speed. Here the distance between these two cars is ignored - they are assumed to have the same position. A car fleet is some non-empty set of ... Read More

Suppose we have a string S of lowercase letters, and an integer array shifts. The shift of a letter means the next letter in the alphabet, for z, it will be a. Now for each shifts[i] = x, we want to shift the first i+1 letters of S, x times. We have to find the final string after all such shifts to S are applied. So if the string is “abc” and shifts = [3, 5, 9], then after shifting the first 1 letter of S by 3, will have “dbc”, shifting first two letters of S by 5, we ... Read More

Suppose Rima has a hand of cards, given as an array of integers. Now she wants to shuffle the cards into groups so that each group is size W, and consists of W consecutive cards. We have to check whether it is possible or not.So if the cards are [1, 2, 3, 6, 2, 3, 4, 7, 8], and W = 3, then the answer will be true, as she can rearrange them like [1, 2, 3], [2, 3, 4], [6, 7, 8]To solve this, we will follow these steps −Define a map m, and store frequency of each element ... Read More

Many different types of data container can get mixed up in python. A list can have elements each of which is a tuple. In this article we will take such a list and find the frequency of element in the tuples which are themselves elements of a list.Using count and mapWe apply a lambda function to count through each of the first element in the tuples present in the list. Then apply a map function to arrive at the total count of the element we are searching for.Example Live Demo# initializing list of tuples listA = [('Apple', 'Mon'), ('Banana', 'Tue'), ('Apple', ... Read More

A given list has many repeated items. We are interested in finding out the sum of the frequency of some such items which are repeated in the list. Below are the approaches how we can achieve this.With sumWe have two lists. One has the list of values and other has the values whose frequency needs to be checked from the first list. So we create a for loop to count the number of occurrences of the elements from the second list in the first list and then apply the sum function to get the final sum of frequency.Example Live Demochk_list= ['Mon', ... Read More

Consider any (contiguous) subarray B (of A) a called mountain if the following properties hold −size of B >= 3There exists some 0 < i < B.length - 1 such that B[0] < B[1] < ... B[i-1] < B[i] > B[i+1] > ... > B[B.length - 1]Suppose we have an array A of integers; we have to find the length of the longest mountain. We have to return 0 if there is no mountain. So if the input is like [2, 1, 4, 7, 3, 2, 5], then the result will be 5. So the largest mountain will be [1, ... Read More