in for循环中的语句

Question

i have a for loop state ment as under:

    for(NSString* name in nameArray)

nameArray is NSArray.

In the above statement, what does it mean for: NSString* name in nameArray

Answer 1

Iterate through all NSString* in nameArray. Can be written less cleanly:

for (int i=0;i<[nameArray count];++i) {
    NSString *name = [nameArray objectAtIndex:i];
    // Do stuff
}

Keep in mind: Don't iterate a mutable array and mutate it (and make sure no other thread does). In such a case you need to call count every iteration like displayed above.

Answer 2

This is fast enumeration syntax introduced in Objective-C 2.0. Check this tutorial for the details. Also you can Google "objective c fast enumeration" for many other resources available online.

Answer 3

这意味着将对nameArray每个对象执行括号内的代码，您将通过NSString *name变量访问该对象。