Ramkesh

There is no language and database in software industries that you can call as most important. It keeps changing. It's entirely depend upon your requirment. Each languages has its uniqueness and hence important in its domain.

Check below point for further clarification:

Java for Application software developers

C/C++ for System software (Utilities/Device drivers/Embedded Systems) developers.

Python for AI, ML, DL and Data Science application developers.

JS for front-end developers.

C language is considered as the mother language of all the modern programming languages because most of the compilers, Kernels are written in C language, and most of the programming languages follow C syntax, for example C++, Java, C#, X++ etc.

C programming language is the base for other programming languages. So first of all C language is recommended to learn before other programming languages.

First, C++ can do everything C can do, only better. C is the predominant language for embedded systems, not C++. The latter is mostly suited to 32-bit systems, and 32-bit MCUs still have less than a 40% market share. And a lot of 32-bit systems still run without an OS at all (“bare metal”). Those that do are split between using a real-time OS like FreeRTOS, and a variation of Linux. C++ is the most widely used language in embedded systems programming. It is preferred over C to write complex embedded OS. Since C++ provides re-use ability of code (inheritance) and greater modularity ( classes ), it is much easier to update the software, in advanced versions.Also, C++ is mostly used in critical embedded systems (where reliability is of utmost importance) like auto-pilot, medical devices , etc. C++ is the most reliable language.

In C, there are two ways to access data member:

1. Simple Variable

2. Pointer Variable

For pointer variable arrow(->) is used to access data member as given in below example:

#include <stdio.h>
struct student
{
     int id;
     char name[20];
};

int main()
{
     int i;
     struct student record1 = {20, "Ram"};
     struct student *ptr;
 
     ptr = &record1;     //here ptr is pointer variable which is refereing to record1 variable
 
         printf("Record of student: \n");
         printf(" Id is: %d \n", ptr->id);
         printf(" Name is: %s \n", ptr->name);
         return 0;
}