How do I separate an integer into separate digits in an array in JavaScript?
JavascriptArraysDigitsJavascript Problem Overview
This is my code so far:
var n = 123456789;
var d = n.toString().length;
var digits = [];
var squaredDigits = [];
for (i = d; i >= 1; i--) {
var j = k / 10;
var r = (n % k / j) - 0.5;
var k = Math.pow(10, i);
var result = r.toFixed();
digits.push(result);
}
console.log(digits);
But when I run my code I get this: [9, 1, 2, 3, 4, 5, 6, 7, 8]
If anyone can see the problem or find a better solution I would very much appreciate it!
Javascript Solutions
Solution 1 - Javascript
Why not just do this?
var n = 123456789;
var digits = (""+n).split("");
Solution 2 - Javascript
What about:
const n = 123456;
Array.from(n.toString()).map(Number);
// [1, 2, 3, 4, 5, 6]
Solution 3 - Javascript
(123456789).toString(10).split("")
^^ this will return an array of strings
(123456789).toString(10).split("").map(function(t){return parseInt(t)})
^^ this will return an array of ints
Solution 4 - Javascript
I realize this was asked several months ago, but I have an addition to samccone's answer which is more succinct but I don't have the rep to add as a comment!
Instead of:
(123456789).toString(10).split("").map(function(t){return parseInt(t)})
Consider:
(123456789).toString(10).split("").map(Number)
Solution 5 - Javascript
Modified the above answer a little bit. We don't really have to call the 'map' method explicitly, because it is already built-in into the 'Array.from' as a second argument. As of MDN.
> Array.from(arrayLike[, mapFn[, thisArg]])
let num = 1234;
let arr = Array.from(String(num), Number);
console.log(arr); // [1, 2, 3, 4]
Solution 6 - Javascript
const toIntArray = (n) => ([...n + ""].map(v => +v))
Solution 7 - Javascript
It is pretty short using Array destructuring and String templates:
const n = 12345678;
const digits = [...`${n}`];
console.log(digits);
Solution 8 - Javascript
Assuming the value n
:
const n = 123456789
A minimal ES6 version if you'd like:
String(n).split("").map(Number)
An even shorter but less readable version:
[...String(n)].map(Number)
Want to go even shorter (but less readable)?
[...`${n}`].map(Number)
Shorter you say (and basically illegible)!?
[...""+n].map(Number)
Now you're a real programmer, congrats!
Side note
These aren't really efficient (as most in this thread) since you're allocating 2 arrays instead of 1. Want to be more efficient? Try this which only allocates one array:
var arr = []
var str = String(n)
for (var i = 0; i < str.length; i++) {
arr.push(Number(str[i]))
}
Oldschool but more efficient, huzzah!
Solution 9 - Javascript
It's very simple, first convert the number to string using the toString() method in JavaScript and then use split() method to convert the string to an array of individual characters.
For example, the number is num, then
const numberDigits = num.toString().split('');
Solution 10 - Javascript
This will work for a number greater than 0. You don't need to convert the number into string:
function convertNumberToDigitArray(number) {
const arr = [];
while (number > 0) {
let lastDigit = number % 10;
arr.push(lastDigit);
number = Math.floor(number / 10);
}
return arr;
}
Solution 11 - Javascript
You can get a list of string from your number, by converting it to a string, and then splitting it with an empty string. The result will be an array of strings, each containing a digit:
const num = 124124124
const strArr = `${num}`.split("")
OR to build on this, map each string digit and convert them to a Number
:
const intArr = `${num}`.split("").map(x => Number(x))
Solution 12 - Javascript
Here's an alternative to Nicolás Fantone's answer. You could argue it's maybe a little less readable. The emphasis is that Array.from() can take an optional map function as a parameter. There are some performance gains this way since no intermediate array gets created.
const n = 123456;
Array.from(n.toString(), (val) => Number(val)); // [1, 2, 3, 4, 5, 6]
Solution 13 - Javascript
const number = 1435;
number.toString().split('').map(el=>parseInt(el));
Solution 14 - Javascript
Suppose,
let a = 123456
First we will convert it into string and then apply split to convert it into array of characters and then map over it to convert the array to integer.
let b = a.toString().split('').map(val=>parseInt(val))
console.log(b)
Solution 15 - Javascript
Move:
var k = Math.pow(10, i);
above
var j = k / 10;
Solution 16 - Javascript
var num = 123456789;
num = num.toString(); //'123456789'
var digits = num.split(""); //[ '1', '2', '3', '4', '5', '6', '7', '8', '9' ]
Solution 17 - Javascript
It's been a 5+ years for this question but heay always welcome to the efficient ways of coding/scripting.
var n = 123456789;
var arrayN = (`${n}`).split("").map(e => parseInt(e))
Solution 18 - Javascript
Another method here. Since number in Javascript is not splittable by default, you need to convert the number into a string first.
var n = 123;
n.toString().split('').map(Number);
Solution 19 - Javascript
I ended up solving it as follows:
const n = 123456789;
let toIntArray = (n) => ([...n + ""].map(Number));
console.log(toIntArray(n));
Solution 20 - Javascript
let input = 12345664
const output = []
while (input !== 0) {
const roundedInput = Math.floor(input / 10)
output.push(input - roundedInput * 10)
input = roundedInput
}
console.log(output)
Solution 21 - Javascript
Update with string interpolation in ES2015.
const num = 07734;
let numStringArr = `${num}`.split('').map(el => parseInt(el)); // [0, 7, 7, 3, 4]
Solution 22 - Javascript
var n = 38679;
var digits = n.toString().split("");
console.log(digits);
Now the number n is divided to its digits and they are presented in an array, and each element of that array is in string format. To transform them to number format do this:
var digitsNum = digits.map(Number);
console.log(digitsNum);
Or get an array with all elements in number format from the beginning:
var n = 38679;
var digits = n.toString().split("").map(Number);
console.log(digits);
Solution 23 - Javascript
This is actually the cleanest solution I think.
var n = 123456789;
const digits = (`${n}`).split('')
You put it in a string literal but it is kept as numbers, and then it is split to an array and assigned to digits.
Solution 24 - Javascript
const toIntArray = (n) => ([...n + ""].map(v => +v))