0-9ASCII码：48 - 57
方法一：
//遍历NSString里面的数字
NSString *str = @"ssdg0db9f567dazy";
NSMutableString *strM = [NSMutableString string];
for (int i = 0; i < str.length; i++) {
unichar a =[str characterAtIndex:i];
if (!(a > 47 && a < 58) ) {
//拼接字符串：方法一
NSString *strResult = [str substringWithRange:NSMakeRange(i, 1)];
[strM appendString:strResult];
//拼接字符串：方法二
//[strM appendFormat:@"%c",a];
}
}
NSLog(@“%@",strM);
方法二：利用正则表达式来实现
#import "GJViewController.h"
#import "NSString+Regex.h"
@interface GJViewController ()
@end
@implementation GJViewController
- (void)viewDidLoad
{
[super viewDidLoad];
NSString *str = @"zhang23g114jn889";
NSRegularExpression *regex = [NSRegularExpression
regularExpressionWithPattern:@"\D*"
options:NSRegularExpressionCaseInsensitive | NSRegularExpressionDotMatchesLineSeparators
error:nil];
NSArray *result = [regex matchesInString:str options:0 range:NSMakeRange(0, str.length)];
NSMutableString *strM = [NSMutableString string];
for (NSTextCheckingResult *resultCheck in result) {
if (resultCheck.range.length > 0) {
[strM appendString:[str substringWithRange:resultCheck.range]];
}
}
NSLog(@"%@",strM);
}