Sort an array into two arrays

userHY7m1 0
Viewed 68

I generated an array with 10 random numbers and I need to sort out these numbers into two new arrays, depending if the generated number is inferior or superior (or equal to 50). My solution seemed to work fine at first but then I noticed the first number generated is always missing after I sorted it. I tried different things but no luck so far... Any recommendation? Thanks!

const arr = Array(10)
  .fill()
  .map(() => Math.round(Math.random() * 100));

console.log(arr);



let arr1 = [];
let arr2 = [];

arr.sort((a) => {
  if (a < 50) {
    arr1.push(a);
  } else {
    arr2.push(a);
  }
});

document.getElementById("arrPrint").innerHTML = JSON.stringify(arr1);

document.getElementById("arrPrint2").innerHTML = JSON.stringify(arr2);
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  <meta http-equiv="X-UA-Compatible" content="IE=edge" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>Document</title>
</head>

<body>
  <pre id="arrPrint"></pre>
  <pre id="arrPrint2"></pre>
  <script src="./index.js"></script>
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sorting arrays javascript
5 Answers

You have to sort and place in arrays as two separate actions. First sort the array, then iterate through the sorted array with arr.forEach

arr = arr.sort();

arr.forEach((a) => {
  if (a < 50) {
    arr1.push(a);
  } else {
    arr2.push(a);
  }
});
Andreas Winther Moen0

Please try the following code. In here, sort function still in the code, then loop the array using forEach

const arr = Array(10)
  .fill()
  .map(() => Math.round(Math.random() * 100));

let arr1 = [];
let arr2 = [];

arr.sort();

arr.forEach((a) => {
  if (a < 50) {
    arr1.push(a);
  } else {
    arr2.push(a);
  }
})

console.log(arr1)
console.log(arr2)
MONSTEEEER0

lodash if you don't mind.

Please pay attention how you can fill array with random numbers.

Live Demo:

const arr = Array.from({length: 10}, () => Math.floor(Math.random() * 100));

const [arr1, arr2] = _.partition(arr, (num) => num < 50);

console.log("arr1: ", ...arr1);
console.log("arr2: ", ...arr2);
.as-console-wrapper { max-height: 100% !important; top: 0 }
<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.21/lodash.min.js"></script>

A1exandr Belan0

try put the filter in variable

const arr = Array(10)
  .fill()
  .map(() => Math.round(Math.random() * 100));

console.log(arr);

arr.sort()

let arr1 = arr.filter(int=> int < 50)
let arr2 = arr.filter(int=> int >= 50)

console.log(arr1)
console.log(arr2)
Feis0 
const getRandomNo = max => {
    return Math.floor(Math.random() * max) + 1;
};
const randomNos = Array.from({ length: 10 }).map(el => {
    return getRandomNo(100);
});

//sort the numbers
const nosGreaterThan50 = randomNos.filter(no => {
    return no > 50;
});

//get the number less than 50
const nosLessThan50 = randomNos.filter(no => {
    return no < 50;
});

console.log(nosGreaterThan50);

console.log(nosLessThan50);
404Xavier60
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