For loop undefined in js

JavaScript
1 
function modulus(num){
  var stored = [];
  for (var i = 0; i < num; i++){
    if ( num[i]%4 == 3){
     stored.push(num[i]);
     return stored;
    }  
  }
}
console.log(modulus(100));

I have no idea why it’s still show undefined when I create a function.

2

Hey @beerbluedevils!

The issue is here.

num [i]

//translation
100[0]

So the computer is confused about what to do with that information

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3

How to write function in the right way?
When I write pure for loop it works well.
I try to fix the function many times but it doesn’t work.

4

What is the problem that you are trying to solve? Is this a homework assignment? A coding challenge?

Are you trying to find all of the numbers from 0-99 that when divided by 4 give you a remainder of 3?

If you could provide more details on what you want the function to accomplish that would help.

Thanks!

5

Hi @beerbluedevils.
Do you know what this code does?

num[i]%4 == 3

You are passing 100 to modulus and then doing 100[i] in the if condition. Don’t you see a problem there? Even if what you did was right, you are returning from an if condition. If the condition doesn’t evaluate to true, what will the function return?

1 Like
6

I try to write the function to find the number from 0-100 that modulus 4 and remain 3.

7

Change the above to i % 4 == 3 and return stored after exiting the loop and make sure to populate store with the right values not undefined. Assuming by " modulus 4 and remain 3" you mean “gives remainder 3 when divided by 4”.

1 Like
8

Also if you want to include the number 100 then you will have to use the <= here

1 Like
9 
var stored = [];
function mod(num){
  for ( var i = 1; i <= num; i++){
    if ( i%4 == 3){
      stored.push(i);
    } 
  }
  return stored;
}
console.log(mod(100));

I can solved it now. The problem is I put the wrong condition in the first time and I put return statement before exiting loop. So I fixed that condition and put the return statement when exiting loop and it works. Thank you guys very much for help me solve this.

2 Likes