// Created By 郭仔 2015年04月02日17:45:01
函數體外部分：
typedef int (^Block)(int ,int );//重命名
typedef void (^Block1)(int );
int n = 0;
=================================================================================================================// 定義函數指針
int (*p)(int ,int) = sum;
//通過函數指針調用函數
int re = p(10,3);
printf("%d\n",re);
// int n = 4;
Block block = ^(int x,int y){
// NSLog(@"%d",n);
return x+y;
};
NSLog(@"%d",block(1,1));
//定義block
int (^block1)(int,int) = ^(int x,int y){
return x+y;
}; //最後分號別忘了
//調用block
int result = block1(10,34);
printf("%d\n",result);
//兩個練手例子
void (^block2)(int) = ^(int num){
printf("%d\n",num);
};
int (^block3)(int) = ^(int year){
return year;
};
block2(4);
printf("%d\n",block3(5));
int (^block4)(NSString *) = ^(NSString * str){
return [str intValue]; //對象方法intValue實現字符串轉化為數值
};
NSLog(@"%d",block4(@"333"));
//printf("%d\n",block4(@"333"));
/*
block是匿名函數：因為調用函數有兩種方式，一種是通過函數名調用，另一種是通過函數指針調用；
通過函數指針調用函數之前，需要給函數指針賦值，也需要用到函數名，所以對於匿名函數來說，這兩種方式都不能實現函數的調用，因此使用block；
block和函數指針非常相似，但是有本質上的區別，但在使用方面，區別不大，我們可以將block當成函數指針，這樣簡化blcok的使用；
*/
__block int x = 10;
// int y;
Block1 block5 = ^(int num){
x++;
// y++;//局部變量
n ++; //全局變量
NSLog(@"%d",x);
NSLog(@"%d",num);
};
block5(5);
/*
1.在block裡面能訪問block之外的局部變量，不能修改block之外的局部變量，如果需要修改，該局部變量前面加__block;
2.在block中可以修改全局變量的值；
3.__block聲明的變量會存儲在內存的全局區（靜態區）
*/
// =================================================================
Car * car1 = [Car carWithType:@"aa" andColor:@"bb" andPrice:134 andMaxSpeed:133 andCostOil:17];
Car * car2 = [Car carWithType:@"cc" andColor:@"dd" andPrice:234 andMaxSpeed:233 andCostOil:27];
Car * car3 = [Car carWithType:@"ee" andColor:@"ff" andPrice:334 andMaxSpeed:333 andCostOil:37];
Car * car4 = [Car carWithType:@"gg" andColor:@"hh" andPrice:434 andMaxSpeed:433 andCostOil:47];
NSMutableArray * cars = [NSMutableArray arrayWithObjects:car1,car2,car3,car4, nil];
//價格從高到低排序 block排序
//若用sortedArrayUsingComparator則需要重新定義一個數組保存（因為有返回值）
[cars sortUsingComparator:^NSComparisonResult(Car *obj1, Car *obj2) {
if ([obj1 price]<[obj2 price]) {
return NSOrderedDescending;
}
else if ([obj1 price] == [obj2 price])
return NSOrderedSame;
else
return NSOrderedAscending;
}];
for (Car *car in cars) {
NSLog(@"%@",car);
}
// maxSpeed從大到小排序，使用sortedUsingComparator
NSArray * arr = [cars sortedArrayUsingComparator:^NSComparisonResult(Car *obj1, Car *obj2) {
if ([obj1 maxSpeed]<[obj2 maxSpeed]) {
return NSOrderedDescending;
}
else if ([obj1 maxSpeed]==[obj2 maxSpeed])
return NSOrderedSame;
else
return NSOrderedAscending;
}];
for (Car * car in arr) {
NSLog(@"%@",car);
}
//自己定義block
NSComparisonResult (^block6)(Car *,Car*) = ^(Car *obj1,Car *obj2){
if ([obj1 maxSpeed]<[obj2 maxSpeed]) {
return NSOrderedDescending;
}
else if ([obj1 maxSpeed]==[obj2 maxSpeed])
return NSOrderedSame;
else
return NSOrderedAscending;
};
//然後調用sort方法，block6傳參過去
[cars sortUsingComparator:block6];
for (Car * car in cars) {
NSLog(@"%@",car);
}
// ==============================================================
//字面量
//數組字面量
NSString * str = @"Literals";
//數組字面量
NSArray * arr1 = @[@"1",@"2",@"3"];
for (NSString * s in arr1) {
NSLog(@"%@",s);
}
//字典字面量
NSDictionary * dic = @{@"name":@"zhangsan",@"age":@"6"};
NSLog(@"%@,%@",dic[@"name"],dic[@"age"]);
NSNumber * num = @123;//把數字123轉化成NSNumber對象
NSLog(@"%@",num);
// ===============================================================
