## Invert Binary Tree

2 likes • Oct 15, 2022
JavaScript

## More JavaScript Posts

### Monotonic Array

CodeCatch
0 likes • Nov 19, 2022
JavaScript
```// Time Complexity : O(N)// Space Complexity : O(1) var isMonotonic = function(nums) {    let isMono = null;    for(let i = 1; i < nums.length; i++) {        if(isMono === null) {            if(nums[i - 1] < nums[i]) isMono = 0;            else if(nums[i - 1] > nums[i]) isMono = 1;            continue;        }        if(nums[i - 1] < nums[i] && isMono !== 0) {            return false;        }        else if(nums[i - 1] > nums[i] && isMono !== 1) {            return false;        }    }        return true;    };
let nums1 = [1,2,2,3]let nums2 = [6,5,4,4]let nums3 = [1,3,2]
console.log(isMonotonic(nums1));console.log(isMonotonic(nums2));console.log(isMonotonic(nums3));```

### Rings and Rods

CodeCatch
0 likes • Nov 19, 2022
JavaScript
```// There are n rings and each ring is either red, green, or blue. The rings are distributed across ten rods labeled from 0 to 9.
// You are given a string rings of length 2n that describes the n rings that are placed onto the rods. Every two characters in rings forms a color-position pair that is used to describe each ring where:
// The first character of the ith pair denotes the ith ring's color ('R', 'G', 'B').// The second character of the ith pair denotes the rod that the ith ring is placed on ('0' to '9').// For example, "R3G2B1" describes n == 3 rings: a red ring placed onto the rod labeled 3, a green ring placed onto the rod labeled 2, and a blue ring placed onto the rod labeled 1.
// Return the number of rods that have all three colors of rings on them.

let rings = "B0B6G0R6R0R6G9";var countPoints = function(rings) {        let sum = 0;    	// Always 10 Rods    for (let i = 0; i < 10; i++) {        if (rings.includes(`B\${i}`) && rings.includes(`G\${i}`) && rings.includes(`R\${i}`)) {            sum+=1;        }    }        return sum;    };
console.log(countPoints(rings));```
```// Vanilla JS Solution:var app = document.getElementById('app');
var typewriter = new Typewriter(app, { loop: true });
typewriter    .typeString("I'm John and I'm a super cool web developer")    .pauseFor(3000)    .deleteChars(13) // "web developer" = 13 characters    .typeString("person to talk with!") // Will display "I'm John and I'm a super cool person to talk with!"    .start();
// React Solution:import Typewriter from 'typewriter-effect';
<Typewriter    options={{ loop: true }}    onInit={typewriter => {        typewriter            .typeString("I'm John and I'm a super cool web developer")            .pauseFor(3000)            .deleteChars(13) // "web developer" = 13 characters            .typeString("person to talk with!") // Will display "I'm John and I'm a super cool person to talk with!"            .start();    }}/>```

### Redux Slice

JoeCamRoberon
0 likes • Mar 11, 2021
JavaScript
```import { createSlice } from "@reduxjs/toolkit";
const alert = createSlice({	name: "alert",	initialState: {	msg: "",	status: "",	},	reducers: {	set_alert: (state, action) => {	return {	...state,	msg: action.payload.msg,	status: action.payload.status,	};	},	clear_alert: (state, action) => {	return {	...state,	msg: "",	status: "",	};	},	},});
export const setAlert = (msg, status) => dispatch => {	dispatch(set_alert({ msg, status }));	setTimeout(() => dispatch(clear_alert()), 4000);};

### getURLParameters

CodeCatch
0 likes • Nov 19, 2022
JavaScript
`const getURLParameters = url =>(url.match(/([^?=&]+)(=([^&]*))/g) || []).reduce(    (a, v) => (      (a[v.slice(0, v.indexOf('='))] = v.slice(v.indexOf('=') + 1)), a    ),    {});`

### MongoDB Connection

CodeCatch
0 likes • Oct 15, 2022
JavaScript
```const MongoClient = require('mongodb').MongoClient;const assert = require('assert');
// Connection URLconst url = 'mongodb://localhost:27017';
// Database Nameconst dbName = 'myproject';
// Use connect method to connect to the serverMongoClient.connect(url, function(err, client) {  assert.equal(null, err);  console.log("Connected successfully to server");
const db = client.db(dbName);
client.close();});```