有人可以解释这个 for 循环是如何工作的吗？

Question

This function returns the largest number from an array. I need help on understanding the if part: if (arr[i] > maxNumber) {maxNumber = arr[i]} . Using pseudocode or an explanation how exactly does this work?

 function max(arr){ let maxNumber = 0 for (i = 0; i < arr.length; i++) { if (arr[i] > maxNumber){ maxNumber = arr[i] } } return maxNumber } console.log(max([1,2,3,40,5]));

Answer 1

function max(array) {
    largest number is equal to 0;
    for (i is equal to 0; i is less than the length of array; increment i by 1 each time) {
        if (the item at the current index is greater than the previous largest number) {
            set the largest number to to the item at the current index;
        }
    }
    return largest number which will be 0 if no larger number is found
}

Worth noting that if all values in the array are negative, it will return 0; This will work for negative numbers too.

function max(arr){
    let maxNumber = -Infinity
    for (i = 0; i < arr.length; i++) {
        if (arr[i] > maxNumber){
            maxNumber = arr[i]
        }
    }
    return maxNumber
}

Answer 2

What this part: if (arr[i] > maxNumber) {maxNumber = arr[i]} doing is checking if the current array member is greater than the current maxNumber and if it is changing the maxNumber value to the current array.

In short, max(whatEverArray) will always return zero or the biggest value of the array. and if it return zero, means all the array values are either zero or less than zero.