NSString 检查是否包含该字符

 NSString *temp = @"english, french, japanese, chinese";
 NSString *jap = @"japanese";
 NSRange foundObj=[temp rangeOfString:jap options:NSCaseInsensitiveSearch];
 if(foundObj.length>0) {
     NSLog(@"Yes ! Jap found");
 } else {
     NSLog(@"Oops ! no jap");
 }

 4.从某一个字符串中的一个字符串开始截取

 NSString *a =@"/pubic/evdaily.nsf/vwtrymaindocid/8E88469482579180035442A/$file/测试帐号及信息22.docx";
 NSRange range = [a rangeOfString:@"$file/"];//获取$file/的位置
 NSString *b = [a substringFromIndex:range.location +
 range.length];//开始截取
 NSLog(@"\n b: %@",b);