类型不匹配：无法从int转换为String

Question

public String getMessage (int numEggs) {

    int a = numEggs/12;
    int b = numEggs%12;

    if ( numEggs < 0) {
        System.out.println("Invalid number");
    } else {
        System.out.println("Your number of eggs is "+ a +" dozen(s) and "+ b+".");
        return;
    }
}

因此，我不断收到Type mismatch: cannot convert from int to String当我尝试在返回值中输入内容时， Type mismatch: cannot convert from int to String ； 代码有什么问题？ 我必须使用getMessage (int numEggs)因为它是我给出的问题的一部分。

Answer 1

无法将int转换为String”，当我尝试在返回内容中输入内容时，

该方法要求您返回一个字符串。 所以你不能做：

return 1; //ie 1, does not get automatically converted to "1"

但是您可以：

return "I'm a String";

Answer 2

我没有看到Type mismatch: cannot convert from int to String但是错误是： This method must return a result of type String

您在方法中缺少return语句：

public String getMessage(int numEggs) {

    int a = numEggs / 12;
    int b = numEggs % 12;

    if (numEggs < 0) {
        return "Invalid number";
    } else {
        return "Your number of eggs is " + a + " dozen(s) and "
                + b + ".";          
    }
}

即使我将getMessage返回类型更改为void也不会给我Type mismatch: cannot convert from int to String

public void getMessage(int numEggs) {

    int a = numEggs / 12;
    int b = numEggs % 12;

    if (numEggs < 0) {
        System.out.println("Invalid number");
    } else {
        System.out.println("Your number of eggs is " + a + " dozen(s) and "
                + b + ".");
        return;
    }
}

Answer 3

您需要返回一个字符串吗？ 如果您只想打印，则只需将返回类型设置为空并删除底部的“ return”即可。

Answer 4

如果要返回字符串：

公共字符串getMessage（int numEggs）{

int a = numEggs/12;
int b = numEggs%12;
String strReturn = "";

if ( numEggs < 0) {
    strReturn = "Invalid number";
} else {
    strReturn = "Your number of eggs is "+ a +" dozen(s) and "+ b+".";

}
return strReturn;

}

如果您想将其打印出来，那么

公共无效的getMessage（int numEggs）{

int a = numEggs/12;
int b = numEggs%12;

if ( numEggs < 0) {
    System.out.println("Invalid number");
} else {
    System.out.println("Your number of eggs is "+ a +" dozen(s) and "+ b+".");
}

}