返回给定字符串的最高和最低编号-Javascript

Question

In this little assignment you are given a string of space separated numbers, and have to return the highest and lowest number.

I know I can find dozens of solution and examples of this one, but I have a case that I really can not figure it out and I would like to know why.

This is the code

 highAndLow = numbers => { var smallestElement = numbers[0]; var highestElement = numbers[0]; numbers = numbers.split(' '); for (var i = 0; i < numbers.length; i++) { if (numbers[i] < smallestElement) { smallestElement = numbers[i]; } console.log(`${numbers[i]} > ${highestElement}`); if (numbers[i] > highestElement) { console.log('----------------------------'); highestElement = numbers[i]; } } return `${highestElement} ${smallestElement}`; }; console.log(highAndLow('4 5 29 54 4 0 -214 542 -64 1 -3 6 12')); 

Considering the example above, my result should be 542 -214 , however I get 6 -214 .

I put two console.log that would print ----------------- when conditions is true, but when I look at the output

How does if(6 > 542) return true ?

Answer 1

The reason you are getting 6 as highest value is because when you are doing if (numbers[i] > highestElement) it is comparing string not a number, and in string 6 is greater than 54 as it compares character by character. so change if (numbers[i] > highestElement) to if (+numbers[i] > +highestElement) (+ will convert string to number)

 highAndLow = numbers => { var smallestElement = numbers[0]; var highestElement = numbers[0]; numbers = numbers.split(' '); for (var i = 0; i < numbers.length; i++) { if (+numbers[i] < +smallestElement) { smallestElement = numbers[i]; } console.log(`${numbers[i]} > ${highestElement}`); if (+numbers[i] > +highestElement) { console.log('----------------------------'); highestElement = numbers[i]; } } return `${highestElement} ${smallestElement}`; }; console.log(highAndLow('4 5 29 54 4 0 -214 542 -64 1 -3 6 12')); 

Answer 2

You are comparing string.Instead you can split the string into an array and use map function to convert each element to integer. Then use sort which will arrange the array and then Math.max/min to get the values

 highAndLow = function(x) { // split the string & map function to convert each element to number var newArray = x.split(' ').map(function(item) { return Number(item) }) return { max: Math.max(...newArray), min: Math.min(...newArray), } }; console.log(highAndLow('4 5 29 54 4 0 -214 542 -64 1 -3 6 12'));