第一、判断是否包含前缀于后缀
NSString *str=@"hello andy yang";
if([str hasPrefix:@"hello"])
{
NSLog(@"the prefix is hello");
}
if([str hasSuffix:@"yang"])
{
NSLog(@"the suffix is yang");
}
第二、NSRange
typedefstruct _NSRange {
NSUInteger location; //开始位置
NSUInteger length; //长度
} NSRange;
NSRange的定义：
NSRange range2;
range2.location = 17;
range2.length = 4;
NSLog(@"%lu and %lu",range2.location,range2.length);
//用NSMakeRange来初始化
NSRange rang1=NSMakeRange(12, 23);
NSLog(@" %lu and %lu",rang1.location,rang1.length);
第三、 rangeOfString函数的使用
NSRange range;
range=[str rangeOfString:@"andy"];
NSLog(@"%lu and %lu",range.location,range.length);
第四、compare实现函数的比较
NSString *str1=@"AA";
NSString *str2=@"aBB";
if ([str2 compare:str1])
{
NSLog(@"%@ is larger than %@",str1,str2);
}else
{
NSLog(@"%@ is larger than %@",str2,str1);
}
第五、NSMutabelString 继承自NSString
- (void)appendString:(NSString *)aString;
- (void)appendFormat:(NSString *)format, ... NS_FORMAT_FUNCTION(1,2);
sample code：
NSMutableString *str=[ NSMutableString stringWithCapacity : 12 ];
[str appendString:@"hello"];
NSLog(@"str is %@",str);
[str appendFormat:@" andy yang %d",11];
NSLog(@"str is %@",str);
- (void)deleteCharactersInRange:(NSRange)range; 删除字符串
NSMutableString *str1=[NSMutableString stringWithFormat:
@"hello what is your name?"];
NSRange range;
range=[str1 rangeOfString:@"what"];
NSLog(@"start is %lu,length is %lu",range.location,range.length);
[str1 deleteCharactersInRange:range];
NSLog(@"str is %@",str1);