Common nsarray and nsmutablearray Methods

/* Initialization method:
1. init returns an empty array
2. initwitharray initializes from an existing array
3. initwithcontentsoffile // load from plist File
4. initwithcontentsofurl // obtain from the network address
5. initwithobject is initialized with an object
6. initwithobjects is initialized from multiple objects.

Self. thedataarray = [[nsmutablearray alloc] initwithcapacity: 5]; // specifies that five elements are initialized.

*/

/* Print the first element:
Nslog (@ "the object is: % @", [thedataarray firstobjectcommonwitharray: thedataarray]);
*/
/* Print the last element:
Nslog (@ "the object is: % @", [thedataarray lastobject]);
*/
/* Enumerate all elements. Method 1:
For (nsstring * thestr in thedataarray ){
Nslog (@ "% @:", thestr );
}
*/
/* Enumerate all elements. Method 2:
For (INT I = 0, I <[thedataarray count], I ++ ){
// Nslog (@ "% @:", [thedataarray objectatindex: I]);
}
*/
/* Enumerate all elements. Method 3: Use the enumerator:
Nsenumerator * enumerator = [thedataarray objectenumerator];
Id OBJ;
While (OBJ = [enumerator nextobject]) {
Nslog (@ "% @", OBJ );
}
*/

/* // Add an element
[Thedataarray addobject: @ "this is the newly added element"]; // Add it from the end
*/

/* // Insert an element from the specified index
[Thedataarray insertobject: @ "this is inerted object" atindex: 0]; // insert to the front of the specified index
*/


/* // Modify. Update Element
[Thedataarray replaceobjectatindex: 0 withobject: @ "New OBJ"]; // modify the specified index
*/

/* // Determine whether the array contains an object

If ([thedataarray containsobject: @ "selectiont"]) {
Nslog (@ "the object selection is contained in array ");
}
Else {
Nslog (@ "not contain ");
}
*/
/* // Obtain the element index
Nslog (@ "The idx is: % I", [thedataarray indexofobject: @ "selection"]);
*/

/* // Sort array elements

Method 1:



Nsarray * thetemparr = [[nsarray alloc] initwitharray: [thedataarray
Sortedarrayusingselector: @ selector (caseinsensitivecompare :)];
*/
// [Thedataarray sortedarrayusingselector: @ selector (caseinsensitivecompare :)]; // or @ selector (compare :)

/* // Sort array elements
Method 2:

Nslog (@ "before sorted array: % @", thedataarray );
Nscountedset * cset = [[nscountedset alloc] initwitharray: thedataarray];

Nsarray * thetemparr = [[nsarray alloc] initwitharray: [[cset allobjects] sortedarrayusingselector: @ selector (compare :)];

Nslog (@ "after sorted array: % @", thetemparr );
*/
/* // Sort array objectsNssortdescriptor
Nssortdescriptor * sortdescriptor = [[nssortdescriptor alloc] initwithkey: @ "name" ascending: Yes]; // @ "name" is the object property
[Thedataarray sortusingdescriptors: [nsarray arraywithobject: sortdescriptor]; // return the sorted Array

// You can also use the custom method: [thedataarray sortusingselector: @ selector (custom method :)];
-(Nsinteger) custommethod :( someobject *) otherobj {
Nscompareresult compareresult = [self. Name compare: otherobj. Name];
If (compareresult = nsorderedsame) return 0;
If (compareresult = nsorderedascending) return 1;
Else return-1;
}
*/

/* // Object array filtering (nspredicate)
Nsarray * keyarray = [[nsarray alloce] initwtihobjects: @ "A", @ "B", nil];
For (nsstring * key in keyarray)
{
// Define the rule:

Nspredicate * apredicate = [nspredicate predicatewithformat: @ "self. Name
Beginswith [c] % @ ", key]; // self. Name is an object attribute, beginswith [c] % @", key
Indicates selecting objects whose names start with key.
// Or:
Nspredicate * apredicate = [nspredicate
Predicatewithformat: @ "self. name contains [c] % @", key]; // contains [c]
% @ ", Key indicates selecting objects whose names contain keys
// Or:
Nsinteger age = 20;
Nspredicate * apredicate = [nspredicate predicatewithformat: @ "self. age> % I", age]; // indicates selecting objects whose age is greater than 20

// Or:
Nsstring * matchstr = @ "El *";
Nspredicate * apredicate = [nspredicate predicatewithformat: @ "self. name like % @", matchstr]; // indicates that the name contains objects similar to the string matchstr.

Nsarray * newarr = [thedataarray filteredarrayusingpredicate: apredicate];
[Thedatadict setvalue: newarr forkey: Key];
}

*/

/* // Delete an array element
Nsmutablearray * temparray = [[nsmutablearray alloc] initwithobjects: @ "one", @ "tow", @ "threr", nil];
[Temparray removeobjectatindex: 0]; // remove from the specified index
[Temparray removeallobjects]; // removes all elements.
[Temparray removelastobject]; // removes the last element.
[Temparray removeobjectsinarray: newarray]; // removes elements from the specified array
[Temparray removeobjectsatindexes: nsindexset * _ strong)]; // remove from the selected index

*/

Reprinted address http://1058813598.diandian.com/post/2011-12-24/10271590