//查找字符串是否包含“心”

   NSString *str = @"每天都有好心情";

   if ([str containsString:@"心"]) {

       NSLog(@"字符串包含“心”");

      //containString适用于ios8系统，在ios7系统下会崩溃

   }

   NSRange range = [str rangeOfString:@"心"];

   if (range.location != NSNotFound) {//有@“心”

       //ios7系统下也适用

       NSLog(@"字符串包含“心”");

   }