如何用JS找到最高和最低的数字？

Question

I would like to know why my code isn't working. There are different ways to solve this issue using Math.max() and Math.min() , however I do not want any other method for this stage as I'm still learning iterations.

Could anyone tell me why this isn't working as I intended? I want to get the highest number and the lowest number from a string, when I run it:

highAndLow("4 5 29 54 4 0 -1 -3209093 -214 -542 -64 -1 -3 -6"); // The result of this is 54 and -3209093 

highAndLow("1 1"); // The result of this is 1 and 0

So as you can see the result for the second try should be 1 and 1 but it gives me 1 and 0.

What did I do wrong here?

function highAndLow(numbers){
    var num;
    var maxNum = 0;
    var minNum =0;
    num = numbers.split(" ").map(Number);

    num.map( function(el){
        if(el >= maxNum) {
            maxNum = el;
        }
        if(el <= minNum) {
            minNum = el;
        }
    });
    console.log(maxNum + ' ' + minNum);
}
highAndLow("4 5 29 54 4 0 -1 -3209093 -214 -542 -64 -1 -3  -6"); **// The result of this is 54 and -3209093**
highAndLow("1 1"); **// The result of this is 1 and 0**

Answer 1

 let arr = [0, 100, 2, 45, 23, 1.5, 45.5]; let min = Math.min(...arr) let max = Math.max(...arr) console.log(min) console.log(max)

Hi, you could use the Math object to obtain min and max values spreading the array as shown above.

Answer 2

It's because you initialize minNum to zero, zero is less than one. That's why the result is 1 and 0.

Answer 3

Try something like this:

 let arr = [0, 2, 45, 23]; let min = arr.reduce((prev, curr) => Math.min(prev, curr), Number.MAX_VALUE); let max = arr.reduce((prev, curr) => Math.max(prev, curr), Number.MIN_VALUE); console.log(min, max);

It goes through every value, and looks if it's higher than the current highest (or lower than the current lowest). For more information on reduce() , look here .

Also look at the answer by @Mario Perez for a slightly more elegant solution