Register Keyword

[Sneha Jariwala]

#53729

What Is The Use Of Register Keyword With The Variables?

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[Nitesh User Do not delete]

#53731

1) Register keyword implies that of conceivable to store the variable in the register than store it in the register.

2) Variables are generally stored in stacks and are passed back and forth to a processor at whatever point required.

3) Also, register keyword when utilized decreased code size which is something critical in an embedded system.

Registers are quicker than memory to get to, so the variables which are most every now and again utilized in a C program can be placed in registers utilizing register keyword. The keyword register clues to the compiler that a given variable can be placed in a register. It’s compiler’s decision to place it in a register or not.

1) If you use an operator with a register variable then the compiler may give an error or cautioning : –

int main()
{
register int i = 10;
int *a = &i;
printf(“%d”, *a);
getchar();
return 0;
}

2) Register keyword can be utilized with Pointer Variables: –

int main()
{
int i = 10;
register int *a = &i;
printf(“%d”, *a);
getchar();
return 0;
}

3) The register is a storage class, and C doesn’t permit different storage class specifiers for a variable: –

int main()
{
int i = 10;
register static int *a = &i;
printf(“%d”, *a);
getchar();
return 0;
}

There is no restriction on a number of register variables in a C program, yet the fact of the matter is compiler may put a few variables in the register and some not.

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Regards,
Nitesh Bavishiya

[Author]

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