Types, Ranges, Precision

what is covered here?

• signed/unsigned, short/long application for basic datatypes

• program to find datatypes - sizes, ranges and precision for float/double

• ASCII Table

• methods to read or print strings - gets()/puts() vs. scanf()/printf()

• signed/unsigned: can be applied to only int and char; not applicable for float and double.

  • int a; //valid

  • signed int a; //valid

  • unsigned int a; //valid

  • char c; //valid

  • signed char c; //valid

  • unsigned char c; //valid

  • float f; //valid

  • signed float f; //invalid

  • unsigned float f; //invalid

  • double d; //valid

  • signed double d; //invalid

  • unsigned double d; //invalid

• short/long: short/long applicable for int; for double, only long applicable

  • short int a; //valid

  • long int a; //valid

  • short char c; //invalid

  • long char c; //invalid

  • short float f; //invalid

  • long float f; //invalid

  • short double d; //invalid

  • long double d; //valid

If int size is 4 bytes,

unsigned int range ==> [0 to 4294967295]

signed int range ==> [-2147483648 to +2147483647]

int a; / signed int a; ==> for signed int range

unsigned int a; ==> for unsigned int range

/*P2.1 Program to find out the size and limits of data types*/

#include<stdio.h>

#include<limits.h>

#include<float.h>

int main(void)

{

printf("sizeof(char) = %u\n",sizeof(char));

printf("sizeof(short) = %u\n",sizeof(short));

printf("sizeof(int) = %u\n",sizeof(int));

printf("sizeof(long) = %u\n",sizeof(long));

printf("sizeof(float) = %u\n",sizeof(float));

printf("sizeof(double) = %u\n",sizeof(double));

printf("sizeof(long double) = %u\n",sizeof(long double));

printf("SCHAR_MIN = %d\n",SCHAR_MIN);

printf("SCHAR_MAX = %d\n",SCHAR_MAX);

printf("UCHAR_MAX = %d\n",UCHAR_MAX);

printf("SHRT_MIN = %d\n",SHRT_MIN);

printf("SHRT_MAX = %d\n",SHRT_MAX);

printf("USHRT_MAX = %u\n",USHRT_MAX);

printf("INT_MIN = %d\n",INT_MIN);

printf("INT_MAX = %d\n",INT_MAX);

printf("UINT_MAX = %u\n",UINT_MAX);

printf("LONG_MIN = %ld\n",LONG_MIN);

    printf("LONG_MAX = %ld\n",LONG_MAX);

    printf("ULONG_MAX = %lu\n",ULONG_MAX);

printf("FLT_MIN = %e\n",FLT_MIN);

printf("FLT_MAX = %e\n",FLT_MAX);

printf("DBL_MIN = %e\n",DBL_MIN);

printf("DBL_MAX = %e\n",DBL_MAX);

printf("LDBL_MIN = %e\n",LDBL_MIN);

printf("LDBL_MAX = %e\n",LDBL_MAX);

/*Number of digits of precision*/

printf("FLT_DIG = %d\n",FLT_DIG);

printf("DBL_DIG = %d\n",DBL_DIG);

printf("LDBL_DIG = %d\n",LDBL_DIG);

getch();

return 0;

}

methods to read or print strings:

gets() --> end of string --> new line

scanf() --> end of string --> space or newline

puts() --> end of string --> null character

printf() --> end of string --> null character