- (
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
}
转载于:https://www.cnblogs.com/ericiOScnblogs/p/4210845.html
