Objective-c Nsarray method

Nsarray (Array)

Create three string objects

NSString *str1 = [NSString stringwithformat:@ "IPhone4"];

NSString *STR2 = [[NSString alloc] initwithformat:@ "IPhone5"];

NSString *STR3 = @ "IPhone6";

NSLog (@ "%@%@%@", STR1,STR2,STR3);

Nsarray

method 1:initwithobjects because it is an array, you need to pass in multiple objects, which are separated by "," and end with nil.

Create an Array object to receive the incoming objects .

Nsarray *arr1 = [[Nsarray alloc] initwithobjects:str1,str2,str3, nil];

NSLog (@ "%@", arr1);

Method 2:objectatindex: Finding an object by subscript will only find the first conforming object , even after the first object is not displayed , after the first one is found, it returns back .

NSString *str = [arr1 objectatindex:1];

NSLog (@ "%@", str);//nsstring type IPhone5

Nsinteger index = [arr1 INDEXOFOBJECT:STR2];

NSLog (@ "%ld", index),//arr1 subscript 1

Method 3: View the number of array elements

Nsinteger count = [arr1 count];

NSLog (@ "%ld", count);// Result: There are 3 elements in arr1

Method 4: Print out individual elements by facilitating

for (int i = 0; i < Arr1.count; i++) {

NSLog (@ "%@", [arr1 objectatindex:i]);

}

Method 5: sort sortedarrayusingselector: @selector (compare:) This method is provided by the system, the interior has been sorted, so know the method is good, There is no need for undue investigation.

Nsarray *sortarray = [arr1 sortedarrayusingselector: @selector (compare:)];

NSLog (@ "%@", Sortarray);

Nsmutablearray (variable group)

Nsmutablearray inheritance and Nsarray so Nsarray method Nsmutablearray can also be used

creating a mutable Array object

Nsmutablearray *mutarray = [[Nsmutablearray alloc] initwithobjects:str1,str3, nil];

Method 1: add addobject

[Mutarray ADDOBJECT:STR1];

[Mutarray ADDOBJECT:STR2];

[Mutarray ADDOBJECT:STR3];

NSLog (@ "%@%@%@", STR1,STR2,STR3);

Method 2: Delete the Removeobjectatindex

[Mutarray removeobjectatindex:1];

[Mutarray removeobjectatindex:0];

[Mutarray Removeobjectatindex:2];

NSLog (@ "%@", Mutarray);

Method 3: swap exchangeobjectatindex:

[Mutarray exchangeobjectatindex:1 withobjectatindex:0];

NSLog (@ "%@", Mutarray);

Method 4: sort sortusingselector: @selector (compare:)

nsstring *str1 = @ "Jack";

nsstring *str2 = @ "Henry";

nsstring *STR3 = @ "Elyse";

nsstring *STR4 = @ "John";

nsstring *STR5 = @ "Justin";

Nsmutablearray *mutablearray = [[nsmutablearray alloc] INITWITHOBJECTS:STR1,STR2,STR3,STR4,STR5, Nil];

[Mutablearray Sortusingselector:@selector (compare:)];

NSLog (@ "%@", Mutablearray);

Method 5: Get the first element of the array firstobject

[Mutablearray firstobject];

NSLog (@ "%@", Mutablearray. Firstobject);

Method 5: get the last element of the array

[Mutablearray lastobject];

NSLog (@ "%@", Mutablearray. Lastobject);

}

return 0;

Objective-c Nsarray method