java - 使用for循环java逆向生成一个数字

Question

所以我尝试使用 for 循环反转 java 中的数字，我得到了正确的值，但我不确定这是否是最好的方法。

package forloops;
/*
% prints the last number in the sequence
/ prints every number except for the last one
*/
public class modulusForLoops {
public static void main(String[]args) {
    int orig = 123456789;
    int num = orig;
    for (int i = 0; i < 1; i++) {
        num = orig % 10; //9
        int secondDigit = orig / 10; //12345678
        int secondDigitPrinted = secondDigit % 10; //8
        int thirdDigit = secondDigit / 10; //1234567
        int thirdDigitPrinted = thirdDigit % 10; //7
        int fourthDigit = thirdDigit / 10; //123456
        int fourthDigitPrinted = fourthDigit % 10; //6
        int fifthDigit = fourthDigit / 10; //12345
        int fifthDigitPrinted = fifthDigit % 10;
        int sixthDigit = fifthDigit / 10; //1234
        int sixthDigitPrinted = sixthDigit % 10; //4
        int seventhDigit = sixthDigit / 10; //123
        int seventhDigitPrinted = seventhDigit % 10; //3
        int eigthDigit = seventhDigit / 10; //12
        int eigthDigitPrinted = eigthDigit % 10; //2
        int lastDigit = eigthDigit / 10; //1
        System.out.println(orig + " reversed is " + num + secondDigitPrinted + thirdDigitPrinted + fourthDigitPrinted + fifthDigitPrinted + sixthDigitPrinted + seventhDigitPrinted + eigthDigitPrinted + lastDigit);
    }
}
}

Answer 1

您可以简单地将其转换为 String 并使用 java.lang.StringBuilder 反转字符串。

int orig = 123456789;
String numString = Integer.toString(orig);
String reversed = "";
for (int i = numString.length() - 1; i >= 0; i--) { // loop through the string from back to front
    reversed += numString.charAt(i); // add each character to the resulting string
}
System.out.println(reversed);

或者

int orig = 123456789;
String numString = Integer.toString(orig); // convert int to String
String reversed = new StringBuilder(numString).reverse().toString(); // reverse string
System.out.println(reversed);