Array operation traversal, sort, reverse order

Array Traversal:

Index traversal

Enumeration traversal:

1. nsenumerator* enumerator = [array objectenumerator];
2. ID e = nil;
3. while (e = [enumerator nextobject])
4. {
5. NSLog (@ "E =%@", e);
6. }

Code block Traversal:

2. Example 1: Enumeration traversal
4. [Array enumerateobjectsusingblock:^ (ID obj, Nsuinteger idx, boolbool *stop) {
6. NSLog (@ "obj =%@", obj);
8. }];
12. Example 2: Enumeration traversal, which encounters an element (Obj=array[idx] that meets the criteria) exits the traversal.
14. [Array enumerateobjectsusingblock:^ (ID obj, Nsuinteger idx, boolbool *stop) {
16. if ([obj isequaltostring:@ "E3"]) {
18. *stop = YES; //Abort traversal, break
20. } Else {
22. *stop = NO; //Continue traversal, continue
24. }
26. }];

Array sorting:

Circular sorting

code block Ordering:

Nsarray *array = @[@12,@23,@8];

Nscomparator Sortblock = ^ (id string1,id string2) {

return [string1 compare:string2];

if ([string1 floatvalue]<[string2 Floatvalue]) {

return nsorderedascending;

}else if ([string1 floatvalue]==[string2 Floatvalue]) {

return nsorderedsame;

}else{

return nsordereddescending;

}

};

Nsarray *sortarray = [array Sortedarrayusingcomparator:sortblock];

NSLog (@ "%@", Sortarray);

}

Array in reverse order:

Traverse reverse Order

Method in reverse order:

[[Array reverseobjectenumerator] allobjects];

Array operation traversal, sort, reverse order