1.NSArray的下标遍历
NSArray *arr = @[p1, p2, p3, p4, p5];
for (int i = 0; i < arr.count; ++i) {
Person *p = arr[i];
[p say];
}
2.NSArray的快速遍历
NSArray *arr = @[p1, p2, p3, p4, p5];
for (Person *p in arr) {
[p say];
}
3.NSArray 使用block进行遍历
[arr enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
NSLog(@"obj = %@, idx = %lu", obj, idx);
Person *p = obj;
[p say];
}];
4.NSArray给所有元素发消息
- 让集合里面的所有元素都执行aSelector这个方法
- -(void)makeObjectsPerformSelector:(SEL)aSelector;
- -(void)makeObjectsPerformSelector:(SEL)aSelector withObject:(id)argument;
// 让数组中所有对象执行这个方法
// 注意: 如果数组中的对象没有这个方法会报错
// [arr makeObjectsPerformSelector:@selector(say)];
[arr makeObjectsPerformSelector:@selector(eat:) withObject:@"bread"];
