C Token example program:

int main()
{
 int x, y, sum;
 x = 5, y = 10;
 sum = x + y;
 Printf (“Sum = %d \n”, sum);
}

From above program C Tokens can be categorized as follows,
main – identifier, which is usually used by linker as the entry point of the regular program
{,}, (,) – delimiter
int – keyword
x, y, sum – Variables
+, = – Operators
main, {, }, (, ), int, x, y, sum – tokens

The post What are C Tokens? first appeared on Student Projects.

Global variables are helpful when many functions in the program use the same data. Storage for global variables is in a fixed region of memory set aside for this purpose by the compiler.

In the following program, the variable count has been declared outside of all functions.

Example:

#include "stdio.h"
int count;  /* count is global  */
void func1(void);
int main(void)
{
  count = 100;
  func1();
  return 0;
}
void func1(void)
{
  printf("count is %
d", count); /* will print 100 */
}

The post What is a global variable? first appeared on Student Projects.

Local variables exist only while the block of code in which they are declared is executing. That is, a local variable is created upon entry into its block and destroyed upon exit. Furthermore, a variable declared within one code block has no bearing on or relationship to another variable with the same name declared within a different code block.

Example:

void func1(void) 
{ 
  int y; 
  y = 10;
}
void func2(void)
{ 
  int y;
  y = -199;
}

The integer variable y is declared twice, once in func1( ) and once in func2( ). The y in func1( ) has no relationship to the y in func2( ). This is because each y is known only to the code within the block in which it is declared.

The C language contains the keyword auto, which can be used to declare local variables. However, since all variables are, by default, assumed to be auto, this keyword is virtually never used.

The post What is a local variable? first appeared on Student Projects.