//  main.m

//  Category练习

#import <Foundation/Foundation.h>

#import "NSString+NJ.h"    //看不到NSString的.h文件。

/*

int countWithStr(NSString *str)

{

    int count = 0;

    for (int i = 0; i < str.length; ++i) {

        unichar c = [str characterAtIndex:i];

        if (c >= '0' && c <= '9') {

            count++;

        }

    }

    return count;

}

 */

int main(int argc, const char * argv[]) {

    /*

     已知一个字符串, 要求找出字符串中所有的阿拉伯数字

     @"a123jj46kfd5jlwf7ld";

     1.计数器思想, 定义一个变量保存结果

     2.遍历字符串, 取出字符串中所有的字符

     */

    NSString *str = @"a1jj46kf1d5jlwf7l9d8";

    /*

//    unichar c = [str characterAtIndex:1];

//    NSLog(@"%c", c);

    int count = 0;

    for (int i = 0; i < str.length; ++i) {

        unichar c = [str characterAtIndex:i];

//        NSLog(@"%c", c);

        if (c >= '0' && c <= '9') {

            count++;

        }

    }

     */

    int count2 = countWithStr(str);

    int count1 = [NSString countWithStr:str];

    int count = [str count];

    NSLog(@"count = %i", count);

    return ;

}

//  NSString+NJ.h

#import <Foundation/Foundation.h>

@interface NSString (NJ)

+ (int)countWithStr:(NSString *)str;

- (int)count;

@end

//  NSString+NJ.m

#import "NSString+NJ.h"

@implementation NSString (NJ)

-(int)countWithStr:(NSString *)str{

    int count=;

    for (int i=; i< str.length; i++) {

        unichar c=[str characterAtIndex:i];

        if (c>=''&& c<='') {

            count++;

        }

    }

}

-(int)count{

    int number=;

    for (int i= ; i< self.length; ++i) {

        unichar c=[self characterAtIndex:i];

        if(c>=''&& c<='');

        number ++;

    }

}

@end

//  Person.h

#import <Foundation/Foundation.h>

@interface Person : NSObject

- (void)test;

@end

//  Person.m

#import "Person.h"

#import "NSString+NJ.h"

@implementation Person

-(void)test{

   NSString *str=@"fds64jkl43fjdslkf";

    int count =[NSString countWithStr:str];

    NSLog(@" count= %i",count);

}

@end