iOS学习——第一天

#import "AppDelegate.h"

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

{

    // Override point for customization after application launch.

    int i=5;

    i=6;

    NSString *simpleString=@"This is a simple string";

    NSLog(@"Hello World!");

    

    simpleString=[simpleString substringToIndex:6];//方法调用［对象名 方法名］

    NSLog(@"%@",simpleString);

    

    NSArray *array=[[NSArray alloc] initWithObjects:@"One",@"Two",@"Three",@"Four", nil];//数组定义

    NSLog(@"%@",array);//输出格式

    NSLog(@"%d",1);

    

    return YES;

}

Output:

函数定义方法：

一个参数 －(void)SetNumber:(int)number;

多个参数 －[(void)ExchangeNumber:(int)num1 number2:(int)num2;//函数名：ExchangeNumber:number2: