content:
- length:NSUInteger,%ld
- characterAtIndex: it isn't get the string but the unichar
NSString *string = @"Abhd";
NSLog(@"%hu",[string characterAtIndex:0]);
unichar ch = [string characterAtIndex:0];
if (ch == 'A') {
NSLog(@"%u",ch);
}
NSString *string1 = @"A String";
NSString *string2 = @"String";
NSLog(@"string1:%@",[string1 uppercaseString]);//大写
NSLog(@"string2:%@",[string2 lowercaseString]);//小写
NSLog(@"string2:%@",[string2 capitalizedString]);//首字母大小
substringToIndex: 从字符串的开头一直截取到指定的位置，但不包括该位置的字符
NSString *string1 = @"This is a string";
NSString *string2 = [string1 substringToIndex:3];
substringToIndex: 从字符串的开头一直截取到指定的位置，但不包括该位置的字符
NSString *string1 = @"This is a string";
NSString *string2 = [string1 substringToIndex:3];
substringWithRange: //按照所给出的位置，长度，任意地从字符串中截取子串
NSString *string1 = @"This is a string";
NSString *string2 = [string1 substringWithRange:NSMakeRange(0, 4)];
rangeOfString: //查找字符串某处是否包含其它字符串
NSString *string1 = @"This is a string";
NSString *string2 = @"string";
NSRange range = [string1 rangeOfString:string2];
NSInteger location = range.location;
NSInteger leight = range.length;
NSString *astring = [NSString stringWithFormat:@"Location:%ld,Leight:%ld",location,leight]];
NSLog(@"astring:%@",astring);
附：
NSRange的两个属性：
location,
length
-appendString: and -appendFormat: //把一个字符串接在另一个字符串的末尾
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"hello"];
[String1 appendString:@",Liang Girl 11"];
NSString *string2 = @",Liang Girl 22";
[String1 appendFormat:@"%@",string2];
[String1 appendFormat:@",Liang Girl 33"];
NSLog(@"String1:%@",String1);
-insertString: atIndex: //在指定位置插入字符串
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
[String1 insertString:@"Hi! " atIndex:0];
NSLog(@"String1:%@",String1);
-setString:
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
[String1 setString:@"Hello Word!"];
NSLog(@"String1:%@",String1);
-replaceCharactersInRange: withString: //用指定字符串替换字符串中某指定位置、长度的字符串
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
[String1 replaceCharactersInRange:NSMakeRange(0, 4) withString:@"That"];
NSLog(@"String1:%@",String1);
-hasPrefix: //检查字符串是否以另一个字符串开头
- hasSuffix:
NSString *String1 = @"NSStringInformation.txt";
[String1 hasPrefix:@"NSString"] = = 1 ? NSLog(@"YES") : NSLog(@"NO"); [String1 hasSuffix:@".txt"] = = 1 ? NSLog(@"YES") : NSLog(@"NO");
从字符串分割到数组－ componentsSeparatedByString:
NSString *string = @"One,Two,Three,Four";
NSLog(@"string:%@",string);
NSArray *array = [string componentsSeparatedByString:@","];
NSLog(@"array:%@",array);
从数组合并元素到字符串- componentsJoinedByString:
NSArray *array = [[NSArray alloc] initWithObjects:@"One",@"Two",@"Three",@"Four",nil];
NSString *string = [array componentsJoinedByString:@","];
NSLog(@"string:%@",string);
查找与替换
-(NSString *)stringByReplacingCharactersInRange:(NSRange)range withString:(NSString *)replacement
在给定的范围内查找并替换
-(NSString *)stringByReplacingOccurrencesOfString:(NSString *)target withString:(NSString *)replacement
按照所给出的范围替换的原有的字符
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
[String1 replaceCharactersInRange:NSMakeRange(0, 4) withString:@"That"]; // 用于NSMutableString
NSLog(@"String1:%@",String1);
扩展：
- stringByReplacingCharactersInRange
以前解析html的时候，不知道该怎么做，勉强做出来的效果还不好，以后可以用这个试试了。
摘自：http://blog.csdn.net/yqmfly/article/details/12944391
在做标签过滤的时候，用了如下代码，结果内存几秒钟就达到饱满了。
while ((ran = [str rangeOfString:@"<[^>]+>" options:NSRegularExpressionSearch]).location != NSNotFound){
str = [str stringByReplacingCharactersInRange:ran withString:@""];
}
后来修改了一下，把str拆分了，内存增长就没那么快了。
贴一下网页标签过滤的代码。
- (NSString *)filterHtmlTag:(NSString *)originHtmlStr{
NSRange ran;
NSArray *arrMyStr = [originHtmlStr componentsSeparatedByString:@"\n"];
NSMutableString *strOrg = [NSMutableString string];
for (int iArr=0;iArr < [arrMyStr count] ;iArr++) {
NSString *strArr = [arrMyStr objectAtIndex:iArr];
while ((ran = [strArr rangeOfString:@"<[^>]+>" options:NSRegularExpressionSearch]).location != NSNotFound){
strArr = [strArr stringByReplacingCharactersInRange:ran withString:@""];
}
if (strArr.length > 0) {
[strOrg appendString:strArr];
}
}
return strOrg;
}
- rangeOfString
摘自：http://blog.sina.com.cn/s/blog_7b9d64af01019q2m.html
在查资料的时候，无意间发现了一个好方法：组合URL。其中，用到了rangeOfString方法：查找字符串。那就手下把：
-(NSURL*)smartURLForString:(NSString*)str
{
NSURL * result;
NSString * trimmedStr;
NSRange schemeMarkerRange;
NSString * scheme;
result = nil;
// 去除空白
trimmedStr = [strstringByTrimmingCharactersInSet:[NSCharacterSetwhitespaceCharacterSet]];
if ( (trimmedStr != nil) && (trimmedStr.length != 0) ) {
schemeMarkerRange = [trimmedStr rangeOfString:@"://"];
if(schemeMarkerRange.location ==NSNotFound) {
result =[NSURL URLWithString:[NSString stringWithFormat:@"http://%@", trimmedStr]];
} else {
scheme =[trimmedStr substringWithRange:NSMakeRange(0, schemeMarkerRange.location)];
assert(scheme != nil);
if( ([scheme compare:@"http" options:NSCaseInsensitiveSearch] == NSOrderedSame)
|| ([schemecompare:@"https" options:NSCaseInsensitiveSearch] == NSOrderedSame) ) {
result = [NSURL URLWithString:trimmedStr];
}else {
//It looks like this is some unsupported URL scheme.
}
}
}
return result;
}
- 如何打印NSRange
NSLog(@"%@",NSStringFromRange(range));
同类技巧：使用对应的转换
NSStringFromCGPoint
NSStringFromCGSize
NSStringFromCGRect
NSStringFromCGAffineTransform
NSStringFromUIEdgeInsets
