Objective-C 字符串操作

字符串中查找指定字符方法

//开头

-(BOOL) hasPrefix:(NSString *)aString;

//结尾

-(BOOL) hasSuffix:(NSString *)aString;

//中间

-(NSRange) rangeOfString:(NSString *)aString;

例如：

NSString *filename = @"draft-chapter.pages";
if([filename hasPrefix:@"draft"])
{
}
if([filename hasSuffix:@".mov"])
{
}

NSRange range;
range = [filename rangeOfString:@"chapter"];
返回 range.start = 6 range.length = 7
如果没有找到 range.start = NSNotFound