如何讀取Java中每個數字的每個數字

Question

我想運行一個程序，輸出整數中輸入的每個數字的總和。我將如何閱讀數字並輸出每個數字？

示例：輸入爲4053，輸出爲「4 + 0 + 5 + 3 = 12」。

import java.util.Scanner; 

public class Digits{ 
    public static void main(String args[]) { 
    //Scans in integer 
     Scanner stdin = new Scanner(System.in); 
     System.out.println("Enter in a number: "); 
     int number = stdin.nextInt(); 

     //Set sum to zero for reference 
     int sum = 0; 
     int num = number; //Set num equal to number as reference 

     //reads each digit of the scanned number and individually adds them         together 
     //as it goes through the digits, keep dividing by 10 until its 0. 
     while (num > 0) { 
      int lastDigit = num % 10; 
      sum = sum + lastDigit; 
      num = num/10; 
     } 
    } 
} 

這是我用來計算個人數字總和的代碼，現在我只需要幫助輸出個人數字。任何提示和技巧將不勝感激。

Answer 1

我不知道你所說的輸出，但不是這個意思，你可以理解爲串號，並採取每一個字符，並將其解析爲整數

 Scanner stdin = new Scanner(System.in); 
    System.out.println("Enter in a number: "); 
    String number = stdin.next(); 
    int[] result = new int[number.length]; 
    for(int i=0;i<number.length;i++) { 
     result[i] = Integer.parseInt(number.charAt(i)+""); 
     } 
    return result; 

Answer 2

你可以看一下這像String，然後除以號碼。

final Scanner s = new Scanner (System.in); 
    final String line = s.nextLine().trim(); 
    final char [] array = line.toCharArray(); 

    int sum = 0; 
    for (final char c : array) 
    { 
    if (!Character.isDigit (c)) 
    { 
     throw new IllegalArgumentException(); 
    } 

    sum = sum + Character.getNumericValue (c); 
    } 

    System.out.println ("sum = " + sum); 

Answer 3

import java.util.Scanner; 

public class Digits{ 
    public static void main(String args[]) { 
    //Scans in integer 
     Scanner stdin = new Scanner(System.in); 
     System.out.println("Enter in a number: "); 
     int number = stdin.nextInt(); 

     //Set sum to zero for reference 
     int sum = 0; 
     int num = number; //Set num equal to number as reference 

     //reads each digit of the scanned number and individually adds them         together 
     //as it goes through the digits, keep dividing by 10 until its 0. 
     String numToString = ""; 

     while (num > 0) { 
      int lastDigit = num % 10; 
      numToString +=lastDigit+" + "; 
      sum = sum + lastDigit; 
      num = num/10; 
     } 
     //eliminate the last + sign 
     numToString = numToString.substring(0,numToString.lastIndexOf("+")).trim(); 
     System.out.println(numToString +" = " +sum); 
    } 
} 

Answer 4

沒有掃描儀，你可以做

StringBuilder sb = new StringBuilder(); 
String sep = ""; 
int ch; 
long sum = 0; 
while((ch = System.in.read()) > ' ') { 
    if (ch < '0' || ch > '9') { 
     System.out.println("Skipping " + (char) ch); 
     continue; 
    } 
    sb.append(sep).append((char) ch); 
    sep = " + "; 
    sum += ch - '0'; 
} 
sb.append(" = ").append(sum); 
System.out.println(sb); 

Answer 5

試試這個：

import java.util.*; 

public class Digits { 

    public static void main(String [] args) 
    { 
     Scanner input = new Scanner (System.in); 

     System.out.println("Enter number -> "); 
     int number = input.nextInt(); 
     int sum = 0; 

     String numStr = "" + number; 

     while(number > 0) 
     { 
      int lastDigit = number % 10; 
      sum += lastDigit; 
      number = number/10; 
     } 

     for(int i = 0; i < numStr.length();i++) 
     { 
      System.out.print(numStr.charAt(i)); 

      // Dont print an extra + operator at the end 
      if(i == numStr.length() - 1) continue; 

      else 
       System.out.print(" + "); 
     } 

     System.out.print(" = " + sum); 
    } 
}