iOS 正则查找字符串中的数字

需求：对字符串中的金额的颜色修改

传统方法：遍历查找

NSString *str = @"投资券5.89元";
if ([str containsString:@"元"])
    {
        NSString *formStr = @"1234567890.";
        NSArray *arr = [str componentsSeparatedByString:@"元"];
        NSString *targetStr = arr.firstObject;
        NSInteger targetLoc;
        if ([formStr containsString:[targetStr substringWithRange:NSMakeRange(targetStr.length-1, 1)]])
        {
            for (NSInteger i=targetStr.length-1; i>=0; i--)
            {
                if (![formStr containsString:[targetStr substringWithRange:NSMakeRange(i, 1)]])
                {
                    targetLoc = i+1;
                    break;
                }
            }
            NSMutableAttributedString *attributedStr = [[NSMutableAttributedString alloc] initWithString:model.desc];
            [attributedStr addAttribute:NSForegroundColorAttributeName value:UI_THEME_COLOR range:NSMakeRange(targetLoc, targetStr.length-targetLoc)];
            self.descLabel.text = nil;
            self.descLabel.attributedText = attributedStr;
        }
        else
        {
            self.descLabel.text = str;
        }
    }
    else
    {
        self.descLabel.text = model.desc;
    }

正则查找

 NSString *str = @"投资券5.89元";
    NSMutableAttributedString *attStr = [[NSMutableAttributedString alloc]initWithString:str];
    NSRange range = [str rangeOfString:@"\\d[\\d.,]*(?=元)" options:NSRegularExpressionSearch];
    if (range.location != NSNotFound) {
        NSString *subStr = [str substringWithRange:range];
        NSLog(@"%@", subStr);
        
        [attStr addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:range];
    }
    self.moneyLabel.attributedText = attStr;