Find longest string in array

Question

I'm supposed to find the longest string in an array, but can't find what's wrong with my code. Something isn't working when trying to debug in Visual Studio Code it just won't detach. Please help me with what's wrong!

Code:

let arr = ["Orebro", "Sundsvall", "Hudriksvall", "Goteborg"];

function long_string(arr){
   let longest="";
   for (let i=0;i<arr.length;i++){
      if (arr[i]>longest){
         longest=arr[i];
      }
   } 
   return longest;
}

long_string(arr)

Can anyone spot the mistake?

Compare the length property in your if condition instead of comparing string. — Mohammad Usman
– Mohammad Usman, Commented Sep 19, 2018 at 18:10

Nina Scholz · Accepted Answer · 2018-09-19 18:09:56Z

4

You need to check the length of the item and the stored longest string.

if (arr[i].length > longest.length) {
//        ^^^^^^^          ^^^^^^^

Just another hint, you could use the first item as start value for longest and start iterating from index 1.

function long_string(arr) {
    let longest = arr[0];
    for (let i = 1; i < arr.length; i++) {
        if (arr[i].length > longest.length) {
            longest = arr[i];
        }
    }
    return longest;
}

let arr = ["Orebro", "Sundsvall", "Hudriksvall", "Goteborg"];

console.log(long_string(arr));

answered Sep 19, 2018 at 18:09

Nina Scholz

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Comments

Nenad Vracar · Accepted Answer · 2018-09-19 18:11:06Z

4

You can use reduce method for this and check length of current string in each iteration.

let arr = ["Orebro", "Sundsvall", "Hudriksvall", "Goteborg"];
let result = arr.reduce((r, e) => r.length < e.length ? e : r, "");
console.log(result)

answered Sep 19, 2018 at 18:11

Nenad Vracar

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2 Comments

G Cadogan Over a year ago

This does not explain what is wrong with the original code.

Koushik Chatterjee Over a year ago

You can ignore the last parameter , "" of reduce for initialization

Luis felipe De jesus Munoz · Accepted Answer · 2018-09-19 18:13:55Z

2

Another way to to it would be sorting and getting the first item

let arr = ["Orebro", "Sundsvall", "Hudriksvall", "Goteborg"];
    
console.log(arr.sort((a,b)=>b.length-a.length)[0])

answered Sep 19, 2018 at 18:13

Luis felipe De jesus Munoz

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6 Comments

Ben Steward Over a year ago

One critique of this method vs. the reduce example is that it takes longer to sort than to iterate only once over every item. Nevertheless, it is a clever solution.

Luis felipe De jesus Munoz Over a year ago

@BenSteward You are right. As far I know the reduce method is O(n) while this is O(n log(n))

Ben Steward Over a year ago

Yep. Still creative though. Can’t resist those one liners.

SoX Over a year ago

Wow, this is way over my knowledge right now! 😅 It was specified in the assignment to not use sort though, still, that was my first try actually. That try wasn't nearly as pretty as this one though.

Luis felipe De jesus Munoz Over a year ago

@SoX It is just practice and the usage of es6 syntax. For example this is your same code in es6 and this as well

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