iphone - 二进制表达式（'double'和'double'）objective-c问题的无效操作数

Question

二进制表达式（'double'和'double'）objective-c问题的无效操作数

-(double)performOperationWith:(double *)operand1 
                         And:(double *)operand2 {

    double result = 0.0;

    result = operand1 + operand2;

    return result;
}

Answer 1

它们是指针，因此您应该取消引用它们：

result = *operand1 + *operand2;

或者更改函数参数：

-(double)performOperationWith:(double )operand1 And:(double )operand2 {...}

Answer 2

只需删除*：

-(double)performOperationWith:(double)operand1  And:(double)operand2 {
    double result = 0.0;
    result = operand1 + operand2;
    return result;
}