iOS 语法新特性-modern syntax（iOS6后，Xcode4.4后，OS X 10.8.2后）

- (void)modernSyntax {

/* 一、语法新特性NSNumber、NSArray、NSDictionary*/

    // ---- NSNumber 新语法 ----

    NSNumber *num = nil;

    // num = [NSNumber numberWithInt:1];

    num = @1;       // numberWithInt/numberWithShort

    num = @1u;      // numberWithUnsignedInt/numberWithUnsignedShort

    num = @'x';     // numberWithChar/numberWithUnsignedChar

    num = @1l;      // numberWithLong

    num = @1lu;     // numberWithUnsignedLong

    num = @1ll;     // numberWithLongLong

    num = @1llu;    // numberWithUnsignedLong

    num = @1.1f;    // numberWithFloat

    num = @1.234;   // numberWithDouble

    num = @YES;     // numberWithBool

    NSUInteger i = 1;

    num = @(i);     //变量用新特性的时候用”()“包起来

    

    //---- NSArray 新语法 ----

    NSArray *array = nil;

    //array = [NSArray arrayWithObjects:@1, @2, @3, nil];

    array = @[@1, @2, @3];  // 初始化（静态变量不能用新特性,旧方法也不行）//static NSArray *aa  = @[@1, @2];

    id obj0 = array[0];      // 获取子元素

    // 遍历方法1

    NSUInteger count = array.count;

    for (NSUInteger i=0; i<count; i++) {

        NSLog(@"%@", array[i]);//

    }

    // 遍历方法2

    for (id obj in array) {

        NSLog(@"%@", obj);

    }

    // 遍历方法3

    [array enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {

        if (*stop == NO) {

            NSLog(@"|idx:%@-obj:%@|", @(idx), obj);

        }

    }];

    

    //---- NSDictionary 新语法 ----

    NSDictionary *dic = nil;

    // dic = [NSDictionary dictionaryWithObjectsAndKeys:@0, @"key0", @1, @"key1", @2, @"key2", nil];

    dic = @{@"key0":@0, @"key1":@1, @"key2":@2};// 初始化方法

    id obj1 = dic[@"key0"];// 获取

    //遍历

    [dic enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {

        if (*stop == NO) {

            NSLog(@"|key:%@-obj:%@|", key, obj);

        }

    }];

    

/* 二、synthesize*/

    //写了@property不用再写@synthesize，Xcode自动合成

}