how to convert an array of strings to array of numbers?

Question

I have this part of project that I need to convert a Number to an Array, then I have to add +1 to every digit I wrote this code, still it return undefined

function Nbr1(a){
    return a.toString().split('').map(Number).forEach( (item, index) => item + 1);
}
console.log(Nbr1(12345))

and I got this result

and when I add console.log to every item in forEach, I got this

The documentation of .forEach() tells you that .forEach() does not return anything: "Return value: undefined." — Andreas
– Andreas, Commented Dec 23, 2021 at 11:30

Gabriel Nuñez de Andrade · Accepted Answer · 2021-12-23 11:56:03Z

1

You don't need to use a forEach after map. map already iterates through the array.

And don't forget to convert the array item to a number with a + before it because you generated an array of strings

function Nbr1(a) {
  return a.toString().split("").map((number) => +number + 1)
}

console.log(Nbr1(12345))

Learn more about map

answered Dec 23, 2021 at 11:56

Gabriel Nuñez de Andrade

4483 silver badges9 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

Andreas Over a year ago

"...because you generated an array of strings" - No, OP did not. The conversion is done by .map(Number) (the capital N makes the difference ;))

Gabriel Nuñez de Andrade Over a year ago

.split returns an array of strings. String.prototype.split()

Andreas Over a year ago

The script is a.toString().split('').map(Number) and .map(Number) does the conversion

Gabriel Nuñez de Andrade Over a year ago

That doesn't make the statement "because you generated an array of strings" wrong

Andreas Over a year ago

"And don't forget to convert the array item to a number with a + before it because you generated an array of strings" - Is wrong because OP converted them into numbers before the +1. You removed the conversion and added it again with the unary +.

|

Peter Pointer · Accepted Answer · 2021-12-23 12:15:46Z

0

See short example below with usage of parseInt(). No extra forEach required.

function Nbr1(a){
    return a.toString().split('').map((number)=>{
        return parseInt(number) + 1
    })    
}
console.log(Nbr1(12345))

edited Dec 23, 2021 at 12:15

Peter Pointer

4,2542 gold badges21 silver badges40 bronze badges

answered Dec 23, 2021 at 11:57

Omer Naeem

162 bronze badges

Collectives™ on Stack Overflow

how to convert an array of strings to array of numbers?

2 Answers 2

6 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

6 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related