ios 类型转换

   NSString *tempA = @"123";  NSString *tempB = @"456";1，字符串拼接 NSString *newString = [NSString stringWithFormat:@"%@%@",tempA,tempB];2，字符转intint intString = [newString intValue];3，int转字符NSString *stringInt = [NSString stringWithFormat:@"%d",intString];4，字符转float float floatString = [newString floatValue];5，float转字符NSString *stringFloat = [NSString stringWithFormat:@"%f",intString];