How To Find The Largest Group Of Numbers In An Array And Return Them Separately In Javascript?

How can I make a function that returns only the numbers greater than the number that I entered? My code here isn't working, and I don't know why. var arr = [1, 2, 3, 4, 5, 6, 7, 8,

Solution 1:

To work with arrays you could use the filter function, it returns a subset of the array with some condition. So, you can simpley do:

var num = 5; //using 5 as an example

a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

var b = a.filter(number =>number > num);

You can put this into an function.

Solution 2:

You need to create a new empty array and fill it with numbers that are bigger than input value.

var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
var num = Number(prompt('number'));

functionFindBiggestNumbers(num) {
  let biggerThanArray = [];

  for (var i = 0; i < arr.length; i++) {
    if (arr[i] > num) {
      biggerThanArray.push(arr[i]);
    }
  }
  return biggerThanArray;
}

console.log(FindBiggestNumbers(num));

Solution 3:

You can start to understand and do some fun things with functional JS.

Similar to the answer from Daladier Sampaio I've used filter to return an array where each element passes a condition (el > num) in the callback function. (filter, reduce, and map were introduced in ES5 and are very useful array methods and well worth learning how to use.)

In this example, I've passed in - and called - a whole function named greaterThan instead.

greaterThan

1) Accepts an argument - n, the number from the prompt in this case

2) Returns an array - the callback function that will operate on each array element. What's interesting about this function is that it carries a copy of num with it when it returns. A function like this that retains a copy of its outer lexical environment like that is called a closure. Understanding what they are and how they work is a useful JS skill, and one that is often picked up on in JS interviews.

const arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
const num = Number(prompt('number'));

// accepts a number and returns a callback function// that accepts an array element and// tests it against the value of `n`functiongreaterThan(n) {
  returnfunction (el) {
    return el > n;
  };
}

// calling greater than with our prompted number// returns that new callback function that checks each// array elementconst out = arr.filter(greaterThan(num));
console.log(out);

Modern JS >= ES6 will allow you to condense the amount of code you have to write using arrow functions. The following one-line code will work in place of the function in the example:

constgreaterThan = n  => el => el > n;

Solution 4:

You could use Array.prototype.filter():

functionFindBiggestNumbers(num) {
  return arr.filter(n => n > num);
}

var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
var number = Number(prompt("Enter a number"));
console.log(FindBiggestNumbers(number));

The alternative is using a nested if statement inside a for loop like so:

First make a new array:

functionFindBiggestNumbers(num) {
    var newArr = [];
}

Then loop through the original array:

functionFindBiggestNumbers(num) {
    var newArr = [];
    for (var i = 0; i < arr.length; i++) {

    }
}

And if you find an element of the array greater than the number, add it to the new array:

functionFindBiggestNumbers(num) {
    var newArr = [];
    for (var i = 0; i < arr.length; i++) {
        if (arr[i] > num) {
            newArr.push(arr[i]);
        }
    }
}

Finally, return the new array:

functionFindBiggestNumbers(num) {
    var newArr = [];
    for (var i = 0; i < arr.length; i++) {
        if (arr[i] > num) {
            newArr.push(arr[i]);
        }
    }
    return newArr;
}

Demonstration:

functionFindBiggestNumbers(num) {
  var newArr = [];
  for (var i = 0; i < arr.length; i++) {
    if (arr[i] > num) {
      newArr.push(arr[i]);
    }
  }
  return newArr;
}

var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
var number = Number(prompt("Enter a number"));
console.log(FindBiggestNumbers(number));