首先新建Category为convert     Category on为NSMutableArray的工程

可以看见.h的文件名为NSMutableArray＋convert.h

.m 文件名为NSMutableArray+convert.m

NSMutableArray＋convert.h文件的写法是

#import <Foundation/Foundation.h>
@interface NSMutableArray (convert)
- (NSMutableArray *)convert:(NSMutableArray *)array;
- (NSArray *)convert1:(NSArray *)array;
- (NSMutableArray *)convert2:(NSMutableArray *)array;
@end

NSMutableArray＋convert.h文件的写法是

#import "NSMutableArray+convert.h"
@implementation NSMutableArray (convert)
- (NSMutableArray *)convert:(NSMutableArray *)array
{NSInteger count = [array count];for (int i = 0; i < count; i++) {for (int j = 0; j < count - i - 1; j++) {// if ([[array objectAtIndex:j] intValue] > [[array objectAtIndex:(j + 1)] intValue]) {//                if([[array objectAtIndex:j] compare:[array objectAtIndex:j + 1]] == -1){if([[array objectAtIndex:j] compare:[array objectAtIndex:j + 1] options:NSNumericSearch] == -1){  //potions  NSNumericSearch = 64,[array exchangeObjectAtIndex:j withObjectAtIndex:(j + 1)];}}}for (NSString *i in array) {NSLog(@"冒泡排序降序：%@", i);}return array;
}
- (NSArray *)convert1:(NSArray *)array
{
//    NSInteger count = [array count];array = [[array reverseObjectEnumerator] allObjects];   //数组倒叙排列for (NSString *i in array) {NSLog(@"数组倒叙输出，用方法%@", i);}return array;
}
- (NSMutableArray *)convert2:(NSMutableArray *)array
{NSInteger count = [array count];for (int j = 0; j < count / 2; j++) {// if ([[array objectAtIndex:j] intValue] > [[array objectAtIndex:(j + 1)] intValue]) {//                if([[array objectAtIndex:j] compare:[array objectAtIndex:j + 1]] == -1){//            if([[array objectAtIndex:i] compare:[array objectAtIndex:j + 1] options:NSNumericSearch] == -1){  //potions  NSNumericSearch = 64,[array exchangeObjectAtIndex:j withObjectAtIndex:(count - j - 1)];}for (NSString *i in array) {NSLog(@"数组倒序输出，交换位置%@", i);}return array;
}
@end

main.m文件中代码

#import <Foundation/Foundation.h>
#import "NSMutableArray+convert.h"
int main(int argc, const char * argv[])
{@autoreleasepool {NSMutableArray *array = [NSMutableArray arrayWithObjects:@"34",@"8",@"32",@"90",@"33",@"78",@"30", nil];[array convert:array];NSMutableArray *array1 = [NSMutableArray arrayWithObjects:@"34",@"8",@"32",@"90",@"33",@"78",@"30", nil];[array1 convert1:array1];NSMutableArray *array2 = [NSMutableArray arrayWithObjects:@"34",@"8",@"32",@"90",@"33",@"78",@"30", nil];[array2 convert2:array2];}return 0;
}

类目Category

• Category也叫分类或类目

• 主要作用是为 没有源代码 的类添加方法。

• 通过Category添加的方法会成为原类的一部分。从而达到扩展一 类的功能。

Category的定义

• 新建文件

• 选择Objective-C Category模板

• 填写类名和分类名

• .h文件添加方法声明

• .m添加方法实现

• 需要使用的地方进行调用。

Category的声明

• NSString+SayHi.h文件

• @interface NSString (SayHi)

• - (void)hi;

• @end

Category的实现

• NSString+SayHi.m文件

• #import “NSString+SayHi.h”

• @implementation NSString(SayHi)

• - (void)hi{

• NSLog(@”这是通过category为NSString添加的hi方法”);

• }

• @end