每次在遞歸語句（java）中打印返回值？

Question

該項目將編寫一個遞歸方法，用於輸出參數並沿每個步驟返回。
這是我到目前爲止有：

public static int summation(int lower, int upper){ 
    if (lower > upper) 
     return 0; 
    else{ 
     System.out.println("Current lower bound: " + lower); 
     System.out.println("Upper bound: " + upper); 
     return lower + summation(lower+1, upper); 
    } 

它幾近完美的，它唯一缺少的是印刷每一次回報。如何做到這一點？

Answer 1

如何：

public static int summation(int lower, int upper){ 
    if (lower > upper) { 
     System.out.println("Returning: 0");    // print before return 
     return 0; 
    } else{ 
     int result = lower + summation(lower+1, upper); 

     System.out.println("Current lower bound: " + lower); 
     System.out.println("Upper bound: " + upper); 
     System.out.println("Returning: " + result);  // print before return 
     return result; 
    } 
} 

Answer 2

public static int summation(int lower, int upper) { 
    if (lower > upper) { 
     return 0; 
    } else { 
     int returned = lower + summation(lower + 1, upper); 
     System.out.println("Current lower bound: " + lower + " | " + "Upper bound: " + upper + " | " + "returned:" + returned); 
     return returned; 
    } 
}