Why this programme shows error at output?

Question

#include<stdio.h>
int main( )
{
int a,x=2,3,4,5;
a=1,2,3,4,5;
printf("%d%d",x,a);
return 0;
}

Answer 1

Actually you have included headerfile wrongly . When you defined values int a,x=2,3,4,5; here 2 is assigned to x but 3,4,5; where these value will store . May be some Compilers won't give warnings or errors but its wrong to define values randomly in one variable . So its error

Answer 2

x =2,3,4,5; here 2 is assigned to x but 3,4 5 are missing their letf operand.. So syntax error..
x = (2,3,4,5); works.
Also for a = (1,2,3,4,5);

Here x=2, x=3, x=4,x=5 happens so finally x retains value 5.
And still give warning as 2,3,4 are unused values..

Edit: header not studio, it is stdio.h