1.常用功能使用
1)初始化
NSString *astring = @"This is a String!";
2)截取
NSString *str = [@"asd" substringFromIndex:1];
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)替换
NSString *str = [@"asdasd" stringByReplacingOccurrencesOfString:@"asd" withString:@"ok"];
6)路径相关
[filepath lastPathComponent];
7)字符串是否为空
if (str.lenght > 0)
8)字符串比较
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.常用扩展功能(类别扩展)
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;
}
4) 是否是邮箱格式
- (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](?:[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]];
}
5) Base64
- (NSString *)base64 {