category应用（计算nssting的数量）

// main.m

// 03-分类应用

// Created by apple on 14-3-18.

#import <Foundation/Foundation.h>

统计一个字符串中,出现的整数的个数

#import "NSString+NSStringExtend.h"

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

{

@autoreleasepool {

// NSString * str = @"ab1d3,5,5,4";

// int count = [NSString numberCountOfString:str];

// NSLog(@"%d",count);

// NSString * str = @"adf378";//字符串对象

// NSLog(@"new %d",[@"adf378" numberOfCount]);

int count = [NSString numberCountOfString:@"12345"];

NSLog(@"%d",count);

}

return 0;

}

// NSString+NSStringExtend.m

// 02-OC中特有的一些语法

// Created by apple on 14-3-18.

#import "NSString+NSStringExtend.h"

@implementation NSString (NSStringExtend)

//ab1c890

+ (int)numberCountOfString:(NSString *)str

{

int count = 0;

//1.把每一个字符拿出来比较

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

{

unichar c = [str characterAtIndex:i];

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

{

count++;

}

return count;

return [str numberOfCount];

}

- (int)numberOfCount

{

int count = 0;

//1.把每一个字符拿出来比较

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

{

unichar c = [self characterAtIndex:i];

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

{

count++;

}

return count;

}

@end