Converting int to String and then String to int array-CodePudding

I've been trying to do this simple program where I need to check which digit of an integer number is the biggest one. So my initial thought was that I shall convert it all into an array and go with the for loop to check which element of an array is biggest. In order to do this I converted integer into String and then characters of the String into elements of an array. I ran into problem and I looked online for solution. What I don't understand is why do I need the " temp.charAt(i) - '0'" part in order to store characters of String as elements of the array. Why can't it be only arrTemp[i] = temp.charAt(i), without the "- '0'" part.

    String temp = Integer.toString(n);
    int arrTemp[] = new int[temp.length()];
    int max = arrTemp[0];
    for(int i = 0; i<temp.length(); i  ) {
        arrTemp[i] = temp.charAt(i) - '0';

CodePudding user response：

'0' is the character '0', not the integer 0. Characters are represented using int values (ascii code).
The ascii code for '0' is the integer value 48.

int n = (int) '0'; //n would be 48.

So, to convert '0' to the integer 0, you need to subtract '0'-'0' = 48-48 = 0

To convert '9' to int 9:

'9' - '0' = 57-48 = 9

See ASCII code

CodePudding user response：

I don't know how to write in JavaScript so I wrote it in Python:

list = []

num = int(input("Number of integers in list: "))

for i in range(1, num   1):
    ele = int(input("Enter integer: "))
    list.append(ele)

print("Largest integer:", max(list))

Source: https://www.geeksforgeeks.org/python-program-to-find-largest-number-in-a-list/