When I create a variable, how does the system know the memory location corresponding to it?

Question

For example, in C if I write:

#include <stdio.h>

int main(){
   int a=10;
   printf("%d",a);
   return 0;
}

how does the computer know the memory address of the variable a?

Simon · Accepted Answer

When the program is compiled all the static variables you create are allocated memory by the compiler

So, take the line...

int a = 10;

The compiler creates a memory location big enough to hold an integer and uses that address to store the number 10 in.

When you print it out on the next line it prints the contents of the memory location you called 'a'

High level languages like C are so people don't have to manually write all their code in assembly language

? · Answer

Part of the compiler's job is a table of variables; type, addresses. Once you compile the code, the table is no longer needed because the machine code has the address where ever it is needed.

When I create a variable, how does the system know the memory location corresponding to it?

2 Answers