IOS path-enumeration Traversal method

For traversal of collection elements (such as nsarray), OC is similar to Java. But there are also differences. Let's take a look at all the methods for traversing the set elements:

1. Index Traversal

Similar to traversing a set by array subscript

1     NSArray *array;2     array = [NSArray arrayWithObjects :@"one",@"two",@"three",nil];3     for (int i = 0; i<[array count]; i++) {4         NSLog([array objectAtIndex:i]);5     }

2. traverse the set through enumeration

 1 NSArray *array; 2     array = [NSArray arrayWithObjects :@"one",@"two",@"three",nil]; 3     NSEnumerator *enumlator; 4     enumlator = [array objectEnumerator]; 5     NSString *string; 6     while (string = [enumlator nextObject]) { 7          { 8              NSLog(string); 9          }10     } 

3. Below is a method that I often use in Java to quickly traverse

NSArray *array;    array = [NSArray arrayWithObjects :@"one",@"two",@"three",nil];         for (NSString *string in array) {         {             NSLog(string);         }    } 

However, this fast traversal is not always usable. It cannot be used on the tiger (Mac OS X 10.4) system. If you need to support the tiger System

Use nsenumerator. Use the first method when you really need to obtain a fixed underlying element.