Task 135 • Max element in the array

alxjspalma

I just wanted to know if there is a more basic solution with what we learn until now (Lecture Loops) or if someone just found another way to do this and wants to share:

★ SOLUTION Nº1

export const maxElement = (arr) => {
  
  let biggest = -Infinity;
    
    for (let i = 0; i < arr.length; i++) {

      if (arr[i] > biggest) {
        biggest = arr[i];
    }
  }

  return biggest;
}

★ SOLUTION Nº2

export const maxElement = (arr) => {
  let maxi = Math.max(...arr);
    return maxi; 
}

★ SOLUTION Nº3

export const maxElement = (arr) => {
  return Math.max.apply(null, arr);
}

★ SOLUTION Nº4

export const maxElement = (arr) => {
  return arr.reduce((a, b) => Math.max(a, b));
}

★ SOLUTION Nº5

export const maxElement = (arr) => {
    return arr.reduce(function (a, b) {
      return (a > b ? a : b);
    });
}

★ SOLUTION Nº6

export const maxElement = (arr) => {
    let len = arr.length, max = -Infinity;
    while (len--) {
      if (arr[len] > max) {
        max = arr[len];
      }
    }
    return max;
}

Coderslang_Master

An alternative to solution #1 would be to set the first element of the array as max.

Using -Infinity will cause you trouble if the array is empty.

sheila

I used a for loop to iterate through the array.

export const maxElement = (arr, n) => {
  for (let i = 0; i < maxElement.length; i++) {
    return Math.max(...arr);
  }
}

Coderslang_Master

sheila Why do you need a loop if you're using Math.max and return a result on the very first iteration of the loop?

sheila

Coderslang_Master I don't understand anymore.

Coderslang_Master

sheila when you write a return statement in the loop, the loop runs only for 1 iteration.

Try to remove the loop and see if the behaviour of your code changes.

export const maxElement = (arr, n) => {
    return Math.max(...arr);
}

alorenz

@Coderslang_Master I see here a lot of new "commands" or even signs we din't learn about in this lesson, e.g. "Math.max", "-Infinity", "null", ".apply", "reduce", "?", etc... How are we supposed to solve this task if we don't learn all these new stuff first? Or is there a different/simpler way of solving it without these new stuff?
In fact, in a previous task I asked what the $ sign was good for and how to use it. The answer was that we would learn about it in further lessons, which hasn't happened so far, yet we continue to use it. Please help. Thanks

Coderslang_Master

alorenz you're not required to know any of "Math.max", "-Infinity", "null", ".apply", "reduce", "?" to solve this task. All you need is a plain for loop. Before the loop, you can assume the max element is the first array element. In a loop you'll need to add an if statement that would update the max element if the current element is greater than max.

Create a new topic with your code and submission results if you still have trouble.

Hemerson

Hello everyone, How could you help me ? Everything runs perfectly when I executed the task but it refuse to submit.

export const maxElement = (arr) => { let max = 0; for (let i = 0; i < arr.length; i++){ max = arr[0]; if (arr[i] > max ) { max=arr[i]; } } return max; }

Coderslang_Master

Hemerson move max = arr[0] outside of the loop. At the moment, you're rewriting its value on every iteration of the loop.

jomer

helper.js

export const maxElement = (arr) => {
  return Math.max(...arr);
}

solution.js

import { maxElement } from './helper.js';

console.log(`The maximum is ${maxElement([1, 2, 3, 4, 5])}`); //  5
console.log(`The maximum is ${maxElement([-1, -4, -5])}`);    // -1

Coderslang_Master

jomer don't try to rush things. Try to solve tasks with what you've learned in the lecture.