[Objective-c 基础

/*
 计算器类
 1>返回π
 2>计算两个整数的平方
 3>计算两个整数的和
 */


#import <Foundation/Foundation.h>

@interface Calculator: NSObject
//方法名:pi
- (double) pi;

//OC方法中，一个参数对应一个冒号:
//方法名：squr:
- (int) squr:(int) num;

//方法名: sumWithNum1:andNum2:
- (int) sumWithNum1:(int)num1 andNum2:(int)num2;

@end


@implementation Calculator
- (double) pi
{
    return 3.14;
}

- (int) squr: (int) num
{
    return num * num;
}

- (int) sumWithNum1:(int)num1 andNum2:(int)num2;
{
    return num1 + num2;
}
@end


int main()
{
    Calculator *c = [Calculator new];
    int d1 = 4;
    int d2 = 5;
    int d3 = 9;
    NSLog(@"PI = %f", [c pi]);
    NSLog(@"%d 的平方是 %d",d1, [c squr: d1]);
    NSLog(@"%d + %d = %d", d2, d3, [c sumWithNum1:d1 andNum2:d3]);
    return 0;
}