在 NSMutableArray 的特定索引处添加对象

如何在 NSMutableArray的特定索引处添加对象？

如何将对象添加到数组的前端？

91913 次浏览

小开

Take a look at the insertObject:atIndex: method of the NSMutableArray class. Adding to the "front" of the array implies index 0.

For example:

NSMutableArray * array = [[NSMutableArray alloc] initWithCapacity:3];
[array addObject:@"b"]; // Contains "b"
[array insertObject:@"a" atIndex:0]; // Contains "a", "b"
[array insertObject:@"c" atIndex:2]; // Contains "a", "b", "c"

小开

最佳答案

[myMutableArray insertObject:myObject atIndex:42];

To add an object to the front of the array, use 0 as the index:

[myMutableArray insertObject:myObject atIndex:0];

小开

Updated for Swift 3:

If you want to Add an object at a specific index of a NSMutableArray, use below a simple line of code:

self.yourMutableArrayName.insert(<#T##newElement: String##String#>, at: <#T##Int#>)

Example: if you want to add string: "Nature" at index: 3

var str = "Nature"
self.yourMutableArrayName.insert(str, at: 3)

// Enjoy..! 