OC Learning Nsarray and Nsmutablearray arrays

Create an Array object, Nsarray an immutable set of variables

[NSNull null] Empty object

Nsarray *arr = [[Nsarray alloc] initwithobjects:@ "234", @ "543", @ "ASB", Nil];

Nsarray *arr1 = @[@ "1 2 3", @ "234", [NSNull null],@ "789"];

Nsarray *ARR3 = [[Nsarray alloc] initwitharray:arr1];

NSLog (@ "%@", ARR3);

Convert c array to OC Array object

NSString *carr[10] = {@ "123", @ "456", @ "789"};

Nsarray *ARR4 = [[Nsarray alloc] Initwithobjects:carr Count:3];

NSLog (@ "%@", ARR4);

Gets the number of array elements

Nsuinteger count = [ARR4 count]; Nsuinteger unsigned Nsinteger signed

NSLog (@ "Count Is:%ld", count);

Gets the specified subscript element

NSLog (@ "%@", [Arr3 objectatindex:1]);

Gets the first element or the last element

NSLog (@ "%@", [Arr3 Firstobject]);

NSLog (@ "%@", [Arr3 Lastobject]);

Get a subset of ARR2

Nsarray *ARR2 = @[@ "111", @ "222", @ "333", @ "444", @ "555", @ "666"];

Take out successive ranges of elements in arr2 as subsets of content

Nsarray *sub1 = [arr2 subarraywithrange:nsmakerange (1, 3)]; Sub1 for the new subset

NSLog (@ "%@", sub1);

Get any element as a subset

1, list of the necessary elements to do the subscript list

Nsmutableindexset *indexs = [Nsmutableindexset indexset];

1-1 Write a list of the subscript to get the element

for (Nsinteger i = 0; i<[arr2 count]; i++) {

if (i% 2! = 0)

//   {

[Indexs addindex:i];

//  }

//}

2. Give the list to the array

Nsarray *sub2 = [arr2 objectatindex:indexs];//gets all the elements in the subscript list, returns an element set composite group

NSLog (@ "sub2 =%@", sub2);

Gets the longest string and the smallest string

Quick Enumeration

Nsarray *ARR5 = @[@ "123456789", @ "222", @ "333", @ "errr", @ "444", @ "5", @ "666"];

Nsinteger maxLength = [arr5[0] length];

Nsinteger minLength = [arr5[0] length];

NSString *maxstring = nil;

NSString *minstring = nil;

for (id obj in ARR5) {

if (maxLength <= [obj length]) {

maxLength = [obj length];

maxstring = obj;

}

if (minLength >= [obj length]) {

minLength = [obj length];

minstring = obj;

}

}

NSLog (@ "maxstring =%@, minstring =%@", maxstring,minstring);

////////////////////////////////////////////////////////////////////

========= variable array =========== variable array ============ variable array ===========//

////////////////////////////////////////////////////////////////////

Creating a mutable Array object

Nsmutablearray *array1 = [[Nsmutablearray alloc] initwithobjects:@ "232", @ "AAA", @ "342", @ "987", @ "876", nil];

Nsmutablearray *array2 = [[Nsmutablearray alloc] initwithobjects:@ "Dada", @ "ZAs", @ "4RFC", @ "7uj", nil];

NSLog (@ "array1 =%@ array2 =%@", array1,array2);

inserting elements

Insert Subscript range 0 <= Index <= count

[Array1 insertobject:@ "JXF" atindex:1];

[Array1 insertobject:@ "WG" Atindex:[array1 count]];//This is to insert the "WG" into the last

[Array1 insertobject:@ "GG" atindex:3];//this is to insert "GG" into the position of subscript 3!

NSLog (@ "array1 =%@", array1);

Delete Element

[Array2 removeallobjects];//Delete all

[Array2 removelastobject];//Delete the last

[Array2 removeobject:@ "ZAs"];

NSLog (@ "%@", array2);

[Array2 removeobject:@ "ZAs" Inrange:nsmakerange (1, 2)];

NSLog (@ "%@", array2);

[Array2 removeobjectatindex:2];//Removes the element that specifies the subscript

[Array2 removeobjectidenticalto:@ "ZAs"];

[Array2 removeobjectidenticalto:@ "ZAs" Inrange:nsmakerange (1, 2)];

If you want to delete a discontinuous element, put the element you want to delete in a list before you delete the manifest

For example, to delete an even-numbered

Nsmutableindexset *indexs = [Nsmutableindexset indexset];

for (int i = 0; i < [array2 count]; i++) {

if (i% 2 = = 0) {

[Indexs addindex:i];

}

}

Remove elements from a list

[Array2 Removeobjectsatindexes:indexs];

NSLog (@ "%@", array2);

Modify the contents of an array

[Array2 replaceobjectatindex:1 withobject:@ "NMB"];

NSLog (@ "%@", array2);

Nsarray *arr = @[@ "", @ "111", @ "AAA"];

[Array2 Replaceobjectsatindexes:indexs Withobjects:arr];

NSLog (@ "%@", array2);

Swapping the contents of an array

[Array2 exchangeobjectatindex:0 withobjectatindex:1];

NSLog (@ "%@", array2);

Using OC to sort arrays in C language

for (int i = 0; i<[array2 count]; i++) {

for (Int J =i+1; J<[array2 count];j++) {

if ([array2[i] length]>[array2[j] length]) {

[Array2 exchangeobjectatindex:i withobjectatindex:j];

}

}

}

NSLog (@ "array2 =%@", array2);

OC Learning Nsarray and Nsmutablearray arrays