objective-C 的Hello World!

//  main.m
//  HelloWorld
//  Created by jimmy.yang on 11-1-24.
//  Copyright 2011 __MyCompanyName__. All rights reserved.

#import <Foundation/Foundation.h>

//定义“几何形状类型”枚举
typedef enum{
	kCircle,
	kRectangle,
	kOblatesShperoid	
} ShapeType;

//定义“几何形状颜色”枚举
typedef enum{
	kRedColor,
	kGreenColor,
	kBlueColor
} ShapeColor;

//定义“几何形状矩形区域”结构
typedef struct{
	int x,y,width,height;
} ShapeRect;


//定义“几何形状”结构
typedef struct{
	ShapeType type;
	ShapeColor fillColor;
	ShapeRect bounds;
}Shape;


//返回“枚举颜色”的名称
NSString *colorName(ShapeColor colorName){
	switch (colorName) {
		case kRedColor:
			return @"red";
			break;
		case kGreenColor:
			return @"green";
			break;	
		case kBlueColor:
			return @"blue";
			break;	
		default:
			return @"no clue";
			break;
	}
}//colorName

//画圆
void drawCircle(ShapeRect bounds,ShapeColor fillColor){
	NSLog(@"drawing a circle at (%d,%d,%d,%d) in %@",bounds.x,bounds.y,bounds.width,bounds.height,colorName(fillColor));
}//drawCircle

//画矩形
void drawRectangle(ShapeRect bounds,ShapeColor fillColor){
	NSLog(@"drawing a rectangle at (%d,%d,%d,%d) in %@",bounds.x,bounds.y,bounds.width,bounds.height,colorName(fillColor));
}//drawRectangle

//画椭圆形
void drawEgg(ShapeRect bounds,ShapeColor fillColor){
	NSLog(@"drawing an egg at (%d,%d,%d,%d) in %@",bounds.x,bounds.y,bounds.width,bounds.height,colorName(fillColor));
}//drawEgg

//画几何形状
void drawShapes(Shape shapes[],int count){
	int i;
	for(i=0;i<count;i++){
		switch (shapes[i].type) {
			case kCircle:
				drawCircle(shapes[i].bounds,shapes[i].fillColor);
				break;
			case kRectangle:
				drawRectangle(shapes[i].bounds,shapes[i].fillColor);
				break;
			case kOblatesShperoid:
				drawEgg(shapes[i].bounds,shapes[i].fillColor);
				break;
			default:
				break;
		}
	}
}//drawShapes


//主程序入口
int main(int argc, char *argv[])
{  
 		
	Shape shapes[3];
	
	ShapeRect rect0 ={0,0,10,30};
	shapes[0].type = kCircle;
	shapes[0].fillColor = kRedColor;
	shapes[0].bounds = rect0;	
	
	ShapeRect rect1 = {30,40,50,60};
	shapes[1].type = kRectangle;
	shapes[1].fillColor = kGreenColor;
	shapes[1].bounds = rect1;
	
	ShapeRect rect2 = {15,18,37,39};
	shapes[2].type = kOblatesShperoid;
	shapes[2].fillColor = kBlueColor;
	shapes[2].bounds = rect2;	
	
	drawShapes(shapes, 3);
	
	return (0);
}

Console窗口的运行结果：

2011-01-25 13:49:05.978 HelloWorld[734:a0f] drawing a circle at (0,0,10,30) in red 2011-01-25 13:49:06.016 HelloWorld[734:a0f] drawing a rectangle at (30,40,50,60) in green 2011-01-25 13:49:06.018 HelloWorld[734:a0f] drawing an egg at (15,18,37,39) in blue