Vcs14
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The document discusses various data types in C including integers, characters, and real numbers. It covers the range and size of different integer types like int, short int, long int, and their signed and unsigned variants. It also discusses how characters are represented and the behavior when integer values exceed the range. The document then covers storage classes like automatic, register, static, and external which determine how variables are stored and scope.
Vcs14
- 1. Data Types in C
- 2. int i ; short int i ; default signed short int i ; i Type of Integers int short int long int signed short unsigned short Specifier: %u Specifier: %i %d %o %x %X 15 bits = value max value 111 1111 1111 1111 32767 Sign bit 0 - Positive 1 - Negative Range:-32768 to +32767 Size: 2 Bytes Range: 0 to 65535 Size: 2 Bytes
- 3. Type of Integers Sign bit 0 - Positive int 1 - Negative 111 1111 1111 1111 1111 1111 1111 1111 short int long int signed unsigned Specifier: %ld long int a 31 bits = value max value 2147483647 long signed long unsigned Specifier: %lu Range: -2147483648 to +2147483647 Size: 4 Bytes Range: 0 to 4294967295 Size: 4 Bytes
- 4. Type of Chars char char ch ; Sign bit 7 bits = value 0 - Positive 1 - Negative signed char unsigned char Specifier: %c Specifier: %c max value 111 1111 127 Range : -128 to + 127 Size : 1 Byte Range: 0 to 255 Size: 1 Byte
- 5. Types of Real Real float double long double Range: -3.4*1038 to +3.4*1038 Size: 4 bytes Specifier: %f Range: -1.7*10308 to +1.7*10308 Size: 8 bytes Specifier: %lf Range: -1.7*104932 to +1.7*104932 Size: 10 bytes Specifier: %Lf 1 - 8 - 23 1 - 11 - 52 1 - 15 - 64 127 1023 16383
- 6. int short int long int signed unsigned signed unsigned char Real signed unsigned float double long double
- 7. Chars With a Sign? char ch = ’A’ ; ch 65 char dh = -15 ; dh -15
- 8. What If We Exceed The Range? signed char ch = 128 ; printf ( ”%d”, ch ) ; -128 Why?
- 9. Why This Bias? char -128 +127 int -32768 +32767 long int -2147483648 +2147483647
- 10. signed char ch = -128 ; Binary of 128 10000000 1’s complement 01111111 2’s complement 10000000 printf ( ”%d”, ch ) ; -128 unsigned char dh = 128 ; signed char eh = 128 ; Binary of 128 10000000 printf ( ”%u”, dh ) ; Binary of 128 10000000 Add 0 for Positive Sign bit 010000000 Store rightmost 8 bits 10000000 printf ( ”%d”, eh ) ; 01111111 +1 10000000 -128 128
- 11. Various Forms signed short int i ; short signed int i ; short int i ; signed int i ; int i ; short i ; signed i ; unsigned short int j ; short unsigned int j ; unsigned int j ; unsigned j ; long signed int k ; signed long int k ; long int k ; long k ; long unsigned int i ; unsigned long int i ; unsigned long i ; signed char ch ; char signed ch ; char ch ; unsigned char dh ; float a ; long double e ; char unsigned dh ; double d ;
- 12. What Is 365? int 365 long int unsigned int unsigned long int 365L 365l 365u 365lu 365ul What Is 3.14? double 3.14 float long double 3.14f 3.14L
- 13. Would This Work main( ) { int i ; for ( i = 0 ; i = 255 ; i++ ) printf ( ”%d %c”, i, i ) ; } char i ; unsigned char i ;
- 14. Stick To Your Guns main( ) { for ( i = 0 ; i 255 ; i++ ) printf ( ”%d %c”, i, i ) ; } unsigned char i ; printf ( ”%d %c”, i, i ) ;
- 15. Storage Classes In C A Complete definition of variable : Type Storage Class
- 16. A Storage Class signifies Storage Default Initial Value Scope Life
- 17. Types of Storage Classes Automatic Register Static External
- 18. Automatic Storage Class Storage Default Initial Value Scope Life Memory Garbage Local to the block in which the variable is defined Till the control is in the block in which the variable is defined
- 19. Automatic Storage Class main( ) { int a ; static int b ; automatic int c ; printf ( ”%d %d %d”, a, b, c ) ; automatic auto } Error ?
- 20. Default Initial Value main( ) { int a ; static int b ; auto int c ; printf ( ”%d%d%d”, a, b, c ) ; } G 0 G
- 21. Which Is Correct? main( ) { int a = 10 ; float a = 3.14 ; . . . . . . . . . . . . . . } main( ) { int a = 10 ; int a = 20 ; . . . . . . . . . . . . . . } TTiipp:: RReeddeeffiinniittiioonn nnoott aalllloowweedd
- 22. Redefinition? main( ) { int a = 10 ; { int a = 20 ; { int a = 30 ; printf ( ”%d”, a ) ; } printf ( ”%d”, a ) ; } printf ( ”%d”, a ) ; } Error ! Why? main ( ) { int a = 20 ; f ( ) ; }f ( ) { printf ( ”%d”, a ) ; } 30 20 10
- 23. Death, But When? main( ) { Won’t die when the control goes to f( ) int i =10, j = 20, k, l ; k = f ( ) ; l = i + j + k ; printf ( ”%d”, l ) ; } f ( ) { int m = 5, n ; n = m * 2 ; return ( n ) ; } Would die when control goes back
- 24. Register Storage Class Storage : Default Initial value : Scope : Life : CPU Registers 14 Each of 2 bytes Central Processing Unit Microprocessor μp
- 25. Different Speeds? main( ) { auto int i ; register int i ; for ( i = 1 ; i = 250 ; i++ ) printf ( ”%d %c”, i, i ) ; } main( ) { for ( i = 1 ; i = 250 ; i++ ) printf ( ”%d %c”, i, i ) ; } Register Storage Class Storage : CPU Registers Default Initial Value : Garbage Scope : Local to the block in which the variable is defined Life : Till the control remains in the block in which the variable is defined
- 26. Be Judicious main( ) { register int i ; register int j = 20 ; for ( i = 1 ; i = 250 ; i++ ) printf ( ”%d %c”, i, i ) ; printf ( ”%d”, j ) ; }