为什么它在字面上在输出结尾返回0

本文介绍了为什么它在字面上在输出结尾返回0的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 #include <iostream> #include <string> using namespace std; /* Function Name: weightConv Purpose: To take the weight and convert the following number to the coressponding weight unit Return : 0 */ double weightConv(double w, string weightUnit) { if (weightUnit == "g" || weightUnit == "G" ) cout << " Mass = " << w * 0.035274 << "oz"; else if (weightUnit == "oz"||weightUnit == "OZ"||weightUnit == "oZ" ||weightUnit == "Oz") cout << " Mass = " << w * 28.3495 << "g"; else if (weightUnit == "kg"||weightUnit == "KG"||weightUnit == "Kg" ||weightUnit == "kG") cout << " Mass = " << w * 2.20462 << "lb"; else if (weightUnit == "lb" ||weightUnit == "LB" ||weightUnit== "Lb" ||weightUnit == "lB") cout << " Mass = " << w * 0.453592 << "kg"; else if (weightUnit == "Long-tn" ||weightUnit == "LONG-TN"|| weightUnit == "long-tn" || weightUnit == "long-ton") cout << " Mass = " << w * 1.12 << "sh tn"; else if (weightUnit == "sh-tn" || weightUnit == "SH-TN") cout << " Mass = " << w / 0.892857 << " Long tons"; // one other converstion that was not listed in the project desription (stones<->tons) else if (weightUnit == "s" || weightUnit == "S") cout << " Mass = " << w * 0.007 << "tons"; else if (weightUnit == "tons" || weightUnit == "Tons" || weightUnit == "TOns" || weightUnit == "TONs"|| weightUnit == "TONS") cout << " Mass = " << w * 142.857 << "stones"; else cout << "Is an unknown unit and cannot be converted"; return 0; }// end of weightCov function int main() { for (;;) { // variable declaration string user; double mass; string unitType; //Prompt user to enter values cout << "Enter a mass and its unit type indicator(g,kg,lb,oz,long-tn,or sh-tn)" << endl; cin >> mass >> unitType; // Output Results cout << weightConv(mass, unitType) << endl; cout << "Would you like to do another calculation?(yes/no)"; cin >> user; //Loop asking user if they want to do another calculation if (user == "yes") { cout << "Enter a mass and its unit type indicator(g,kg,lb,oz,long tn,or sh tn)" << endl; cin >> mass >> unitType; cout << weightConv(mass, unitType) << endl; } else if (user == "no") { return 0; } }// end of for loop }// end of main

程序工作正常，除了一个错误。当结果打印出来时，字面上在结尾添加一个零。我知道我在函数的结尾返回0，但如果返回weightConv（）它是无限递归。任何人可以帮助我，使它只是返回答案，而不是零在结束。提前感谢。

Program works well except for one error. When the results print out it literally adds a zero at the end. I know I am returning 0 at the end of the function but if return weightConv() it's infinite recursion. Can anyone help me so that it just returns the answer and not zero at the end. Thanks in advance.

推荐答案

您只是打印转换后的值，但不会返回。每个if块应该包含返回计算结果的返回语句。

You're just printing the converted value but you're not returning it. Each of those if blocks should contain a return statement returning the result of the computation.