JavaScript-snippets

JavaScript Snippets

How to generate a random number in a given range

// Returns a random number(float) between min (inclusive) and max (exclusive) 

const getRandomNumber = (min, max) => Math.random() * (max - min) + min;

getRandomNumber(2, 10)

 // Returns a random number(int) between min (inclusive) and max (inclusive)

const getRandomNumberInclusive =(min, max)=> {
    min = Math.ceil(min);
    max = Math.floor(max);
    return Math.floor(Math.random() * (max - min + 1)) + min;
}

getRandomNumberInclusive(2, 10);

How to find the difference between two arrays.

const firstArr = [5, 2, 1];
const secondArr = [1, 2, 3, 4, 5];

const diff = [
    ...secondArr.filter(x => !firstArr.includes(x)),					
    ...firstArr.filter(x => !secondArr.includes(x))
];
console.log('diff',diff) //[3,4]


function arrayDiff(a, b) {
    return [
        ...a.filter(x => b.indexOf(x) === -1),
        ...b.filter(x => a.indexOf(x) === -1)
    ]
}
console.log('arrayDiff',arrayDiff(firstArr, secondArr)) //[3,4]




const difference = (a, b) => {
    const setA = new Set(a);
    const setB = new Set(b);

    return [
        ...a.filter(x => !setB.has(x)),
        ...b.filter(x => !setA.has(x))

    ]
};

difference(firstArr, secondArr); //[3,4]
console.log('difference',difference(firstArr, secondArr))