1.常用功能使用
1）初始化
NSString *astring = @"This is a String!"; //固定字符串NSString *str = [NSString stringWithFormat:@"asd%d%@",123,@"ttt"]; //拼組字符串
2）截取
NSString *str = [@"asd" substringFromIndex:1]; //從第幾位開始截到最后NSString *str1 = [str substringToIndex:1]; //從開始位置截到第幾位NSString *str = [[@"asd" substringFromIndex:1] substringToIndex:1]; //從第幾位開始截幾個(gè)字符
3）分解
NSArray *array = [@"asd|tes|mmm" componentsSeparatedByString:@"|"];
4）查找
NSRange range = [@"12rasd124" rangeOfString:@"asd"]; if (range.location != NSNotFound) { NSString *str = [@"12rasd124" substringWithRange:range]; }
5）替換
NSString *str = [@"asdasd" stringByReplacingOccurrencesOfString:@"asd" withString:@"ok"];
6）路徑相關(guān)
[filepath lastPathComponent]; //獲得文件名[filepath pathExtension]; //獲得文件擴(kuò)展名[filtpaht stringByDeletingLastPathComponent]; //獲得文件的所在文件夾路徑[filtpath stringByDeletingPathExtension]; //獲得去除擴(kuò)展名的文件路徑
7）字符串是否為空
if (str.lenght > 0) //不管str是不是nil都可以這么判斷
8）字符串比較
if ([@"asd" isEqualToString:@"asd"]) { }
9）字符串比大小
NSString *stra = @"asd"; NSString *strb = @"dfs"; NSComparisonResult result = [stra compare:strb]; if (result == NSOrderedSame) { } else if (result == NSOrderedAscending) { } else { }
2.常用擴(kuò)展功能(類別擴(kuò)展)
1）md5
-
(NSString )md5HexDigest
{
const char str = [self UTF8String];
unsigned char result[CC_MD5_DIGEST_LENGTH];
CC_MD5(str, strlen(str), result);
NSMutableString *ret = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH];for(int i = 0; i<CC_MD5_DIGEST_LENGTH; i++) {
[ret appendFormat:@"%02X",result[i]];
}
return ret;
}
2）urlEncode
(NSString *)stringEncode {
NSString *encodedString = (NSString )CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (CFStringRef)self, NULL, CFSTR(":/?#[]@!$ &'()+,;="<>%{}|\^~`"), kCFStringEncodingUTF8));
return encodedString;
}(NSString *)stringDecode {
NSString *result = [(NSString *)self stringByReplacingOccurrencesOfString:@"+" withString:@" "];
result = [result stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
return result;
}
3）sizeFromFont-
(CGSize)boundingRectWithSize:(CGSize)size
withTextFont:(UIFont *)font {
if ([self isEqualToString:@""]) {
return CGSizeMake(0, 0);
}
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineBreakMode = NSLineBreakByWordWrapping;
paragraphStyle.lineSpacing = 0;
NSDictionary *attributes = @{NSFontAttributeName:font, NSParagraphStyleAttributeName:paragraphStyle.copy};return [self boundingRectWithSize:size options:NSStringDrawingUsesLineFragmentOrigin attributes:attributes context:nil].size;
}
- 是否是郵箱格式
-
(BOOL)isEmail
{
NSString emailRegEx =
@"(?:[a-z0-9!#$%\&'+/=?\^_{|}~-]+(?:\\.[a-z0-9!#$%\\&'*+/=?\\^_{|}"
@"~-]+)|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\"
@"x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])")@(?:(?:[a-z0-9](?:[a-"
@"z0-9-][a-z0-9])?\.)+a-z0-9?|\[(?:(?:25[0-5"
@"]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-"
@"9][0-9]?|[a-z0-9-][a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21"
@"-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])";NSPredicate *regExPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegEx];
return [regExPredicate evaluateWithObject:[self lowercaseString]];
}
- Base64
-
(NSString *)base64 {
// Create NSData object
NSData *nsdata = [self dataUsingEncoding:NSUTF8StringEncoding];// Get NSString from NSData object in Base64
NSString *base64Encoded = [nsdata base64EncodedStringWithOptions:0];// Print the Base64 encoded string
return base64Encoded;
} -
(NSString *)base64Decoded {
// NSData from the Base64 encoded str
NSData *nsdataFromBase64String = [[NSData alloc] initWithBase64EncodedString:self options:0];// Decoded NSString from the NSData
NSString *base64Decoded = [[NSString alloc] initWithData:nsdataFromBase64String encoding:NSUTF8StringEncoding];return base64Decoded;
}
