Add random element to array : React

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Thu Jun 24 2021 16:12:14 GMT+0000 (Coordinated Universal Time)

Saved by @hisam #array #destructuring #javasc #react.js

import React, { Component } from "react";

class IconList extends Component {
  static defaultProps = {
    options: [
      "angry",
      "anchor",
      "archive",
      "at",
      "archway",
      "baby",
      "bell",
      "bolt",
      "bone",
      "car",
      "city",
      "cloud",
      "couch"
    ]
  };
  constructor(props) {
    super(props);
    this.state = { icons: ["bone", "cloud"] };
    this.addIcon = this.addIcon.bind(this);
  }
  //DON'T DO THIS!!!!
  // addIcon() {
  //   let idx = Math.floor(Math.random() * this.props.options.length);
  //   let newIcon = this.props.options[idx];
  //   let icons = this.state.icons;
  //   icons.push(newIcon);
  //   this.setState({ icons: icons });
  // }

  addIcon() {
    // get random index
    let idx = Math.floor(Math.random() * this.props.options.length);
 	// get new element
    let newIcon = this.props.options[idx];
    // update the state of the icons array (spread icons into new array, add new icon to it)
    this.setState({ icons: [...this.state.icons, newIcon] });
  }
  render() {
    // render newly mapped icons array
    const icons = this.state.icons.map(i => <i className={`fas fa-${i}`} />);
    return (
      <div>
        <h1>Icons: {icons}</h1>
        <button onClick={this.addIcon}>Add New Icon</button>
      </div>
    );
  }
}

export default IconList;

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Only use pure functions when working with mutable types in react

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react

@hisam

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#react.js #redux

Check if token expires and logout user

const [ user, setUser ] = useState(JSON.parse(localStorage.getItem('profile'))); //convert to object

const logout = () =>{
        dispatch({type: 'LOGOUT'});
        history.push("/");
        setUser(null);
    }

    useEffect(()=>{
        const token = user?.token;

        //JWT check if token expired
        if(token){
            const decodedToken = decode(token)
            if(decodedToken.exp*1000 < newDate().getTime()) logout();
        }
        setUser(JSON.parse(localStorage.getItem('profile')))
    },[location])

##javascript ##js #next.js #react.js

Animate header on scroll with Next.js & TailwindCSS

const [animateHeader, setAnimateHeader] = useState(false)

useEffect(() => {
  const listener = () =>
  window.scrollY > 140 ? setAnimateHeader(true) : setAnimateHeader(false)
  window.addEventListener('scroll', listener)
  return () => {
    window.removeEventListener('scroll', listener)
  }
}, [])

// Example usage with TailwindCSS:
<div className={`bg-header/75 transition duration-500 ease-in-out ${animateHeader && 'bg-header/[0.95]'}`}>...</div>

#css #react.js

React Color Gradients

https://codepen.io/marcobiedermann/pen/WNGWzYR

#react.js #javascript #checkboxtoggle

javascript - How to toggle boolean state of react component? - Stack Overflow

function App() {
  const [checked, setChecked] = useState(false);
  const toggleChecked = () => setChecked(value => !value);
  return (
    <input
      type="checkbox"
      checked={checked}
      onChange={toggleChecked}
    />
  );
}

#javascript #react.js

lowercase, uppercase, remove spaces ( trim ) , capitalize first letter

// making all uppercase
city.toUpperCase();

//removing spaces and making all lowercase
city = city.trim().toLowerCase();

//capitalizing the first letter
cityCapitalized = city.charAt(0).toUpperCase() + city.slice(1);

#react.js

Open new window onclick reactJS

onClick={() => window.open(url, "_blank")}

#react.js

Определяет клик вне компонента

import { useEffect } from 'react';

export const useClickOutside = (ref, setIsModalOpen) => {
  useEffect(() => {
    function handleClickOutside(event) {
      if (ref.current && !ref.current.contains(event.target)) {
        setIsModalOpen(false)
      }
    }
    document.addEventListener("mousedown", handleClickOutside);
    return () => {
      document.removeEventListener("mousedown", handleClickOutside);
    };
  }, [ref]);
};

#java #java #stream #array

how to find an element in array of object with streams

itemList.stream()
          .filter(item -> item.getPropertyList()
                         .stream().anyMatch(property -> property.getKey().equals("Test")))
           .collect(Collectors.toList());

#C# #c# #array #dictionary

How to clear item not input when count frequency use Dictionary C#

for (int i = 0; i < n; i++)
{
    if (valCount.ContainsKey(x))
        valCount[x]++;
    else
        valCount[x] = 1;
}

#css #css #items #array

Getting First and Last Items in Array (and splitting all the rest)

 const arr = ["This", "Little", "Piggy"];
const first = arr.slice(0, 1);
const the_rest = arr.slice(1);console.log(first); // ["This"]
console.log(the_rest); // ["Little", "Piggy"]

#php #array

2 dimensional array to 1 dimensional array

$oneDimensionalArray = array_map('current', $twoDimensionalArray);

/*
current() function returns the value of the current element in an array. for ex : $fruits = array("banana", "apple", "orange"); echo current($fruits) //will return "banana" since current pointer is on index 0 which is banana
*/

#javascript #array

Check if two arrays are equal or not

function isEqual(arr1,arr2){
  let x = arr1.length;
  let y = arr2.lenght;
  
  //if lenght of array are not equal means array are not equal 
  if(x !=  y) return false;
  
  //sorting both array
  x.sort();
  y.sort();
  
  // Linearly compare elements
  for(let i=0;i<x;i++){
    if(x[i] != y[i]) return false
  }
  // If all elements were same.
    return true
}

let arrayOne = [3, 5, 2, 5, 2]
let arrayTwo = [2, 3, 5, 5, 2]

isEqual(arrayOne,arrayTwo) ? console.log("Matched") : console.log("Not Match")

#javascript #array #emptyarray

Remove Empty or null element from array

const arr = ["Apple",45,"","google",null],,,,"facebook","",69]

const removeEle = arr.filter((el)=> return el !=null && el != "")

#javascript #array #sort

Sort array

const arr = [333,1,2,11,22,3,4]
console.log(arr.sort())

arr.sort((a,b)=>a-b)

console.log(arr)

#javascript #array #shuffle

Shuffle array and shuffle Selected Index

let items = [1,25,"JavaScript",69,"css","34","keep coding","html"];
console.log(items)

//shuffle array
function shuffle(arr){
  for(let i =arr.length-1;i>0;i--){
    const j = Math.floor(Math.random() * (i+1));
    [arr[i],arr[j]] = [arr[j],arr[i]];
  }
  return arr
}
console.log(shuffle(items))

//shuffle selected index 
const  itemToShuffle = items.slice(3,7);
console.log(shuffle(itemToShuffle))

//items after shuffling item from index 3 to 7
items = [items[0],items[1],items[2],...itemToShuffle,items[7]]
console.log(items)

Add random element to array : React

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