该方法必须返回int类型

Question

public int computeStyle(String season) {
    if(season.equals("summer")){
        if (this.style.equals("toque")){
            return 8;
        }
        if (this.style.equals("sun visor")){
            return 1;
        }
        if (this.style.equals("fedora")){
            return 6;
        }
    }
    else if(season.equals("winter")){
        if (this.style.equals("toque")){
            return 1;
        }
        if (this.style.equals("sun visor")){
            return 8;
        }
        if (this.style.equals("fedora")){
            return 7;
        }
    }
    else return 5;
}

Why do I keep getting the error that the method must return type int. What is wrong with this function? It should return an int in every possible scenario right?

Answer 1

There are two paths that are not covered:

public int computeStyle(String season) {
    if(season.equals("summer")){
        if (this.style.equals("toque")){
            return 8;
        }
        if (this.style.equals("sun visor")){
            return 1;
        }
        if (this.style.equals("fedora")){
            return 6;
        }
        //here
    }
    else if(season.equals("winter")){
        if (this.style.equals("toque")){
            return 1;
        }
        if (this.style.equals("sun visor")){
            return 8;
        }
        if (this.style.equals("fedora")){
            return 7;
        }
        //here
    }
    else return 5;
}

Solution: declare a variable with the defaut return value and assign the value properly:

public int computeStyle(String season) {
    int result = 5;
    if(season.equals("summer")){
        if (this.style.equals("toque")){
            result = 8;
        }
        if (this.style.equals("sun visor")){
            result = 1;
        }
        if (this.style.equals("fedora")){
            result = 6;
        }
    }
    else if(season.equals("winter")){
        if (this.style.equals("toque")){
            result = 1;
        }
        if (this.style.equals("sun visor")){
            result = 8;
        }
        if (this.style.equals("fedora")){
            result = 7;
        }
    }
    return result;
}

Answer 2

If your return type is int, any how your method must return an int.

In this case inside your outer if else , you still have if blocks, means if, inside the outer if else , if non if the condition is satisfied, then it ll return nothing.

In this case, you should always add a return statement at the end.

Like this :

public int computeStyle(String season) {
    if(season.equals("summer")){
        if (this.style.equals("toque")){
            return 8;
        }
        if (this.style.equals("sun visor")){
            return 1;
        }
        if (this.style.equals("fedora")){
            return 6;
        }
    }
    else if(season.equals("winter")){
        if (this.style.equals("toque")){
            return 1;
        }
        if (this.style.equals("sun visor")){
            return 8;
        }
        if (this.style.equals("fedora")){
            return 7;
        }
    }
    else return 5;

   // If everything fails, then it ll return 0 at least
   return 0;
}