在方法java中将字符串转换为int

Question

所以我尝试将int转换为string，然后再转换为charAt（0）、charAt（1）和charAt（2）。我这样做是为了把3位数的整数拆分成3个不同的整数。然后我想把这些整数转换成字符串。

我想做的是从101及以上的数字中提取并用文字打印出来。我有数百种、十种和一种方法。我试着把第一个整数应用到百分法，第二个整数应用到十分法，第三个整数应用到一分法。

这是一种

import java.util.Scanner;


public class rough {

    public static void main(String args[]) {
        int number = 0;
        Scanner scanner = new Scanner(System.in);
        System.out.print("Please type a number between 0 and 999 OR type -1 to exit:  ");
        number = scanner.nextInt();
        if (number >= 101) {
            System.out.println(hundred(first) + " AND" + tens(second) + "" + From1To19(third));
        } else {
            System.out.println("please input a number from 101: ");
        }
        //this is what i have so far(might be junk).

    public static void From101(int num) {
        String SNumber = Integer.toString(num);
        char First = SNumber.charAt(0);
        char Second = SNumber.charAt(1);
        char Third = SNumber.charAt(2);
        int num1 = Integer.parseInt(first);
    }
}

现在我正试着打印单词，我发现了3个错误。

System.out.println(hundred(first) + " AND" + tens(second) + "" + From1To19(third));

我在if/else语句中添加该行，错误是：

 ----jGRASP exec: javac -g rough.java

rough.java:27: error: 'void' type not allowed here
                           System.out.println(hundred(first) + " AND" + tens(second) + "" + From1To19(third));
                                                     ^
rough.java:27: error: 'void' type not allowed here
                           System.out.println(hundred(first) + " AND" + tens(second) + "" + From1To19(third));
                                                             ^
rough.java:27: error: 'void' type not allowed here
                           System.out.println(hundred(first) + " AND" + tens(second) + "" + From1To19(third));
                                                                                     ^
3 errors

 ----jGRASP wedge2: exit code for process is 1.
 ----jGRASP: operation complete.

Answer 1

这对你来说很好，而。。。。在这方面，你可以增加你的数字范围。。。。

导入java.util.扫描仪；

public class rough {

    public static void main(String args[]) {
        int number = 0;
        Scanner scanner = new Scanner(System.in);
        System.out.print("Please type a number between 0 and 999 OR type -1 to exit:  ");
        number = scanner.nextInt();
        if (number >= 101) {
            From101(number);
        } else {
            System.out.println("please input a number from 101: ");
        }
        //this is what i have so far(might be junk).

    public static void From101(int num) {
       while(num>0)
       {
         d=num%10;
         System.out.print(d + " ");
         num=num/10;
       }
    }
}

Answer 2

这对你有帮助吗。

public static void main(String args[]) {
        int number = 0;
        Scanner scanner = new Scanner(System.in);
        System.out.print("Please type a number between 0 and 999 OR type -1 to exit:  ");
        number = scanner.nextInt();
        if (number >= 101) {
            From101(number);
        } else {
            System.out.println("please input a number from 101: ");
        }

    }

    private static void From101(int num) {
        String SNumber = Integer.toString(num);
        int num1 = Character.getNumericValue(SNumber.charAt(0));
        int num2 = Character.getNumericValue(SNumber.charAt(1));
        int num3 = Character.getNumericValue(SNumber.charAt(2));
        System.out.println(num1 + " " + num2 + " " + num3);
    }

输出

Please type a number between 0 and 999 OR type -1 to exit:  101
1 0 1

参考这个

Answer 3

现在，您正在将int转换为String，String转换为chars，并将char转换回int。

您可以跳过所有这些，直接从int-

例如，要获取12345的各个数字：

int a = 12345;
int b = a%10; //b = 5
a = a / 10; //now a = 1234
int c = a%10; //c = 4
a = a / 10; //now a = 123
int d = a%10; //d = 3
a = a / 10; //now a = 12
int e = a%10; //e = 2