tailieunhanh - Lecture Introduction to Computer Programming - Lecture 21

This section addresses the question of program correctness functional programming. We visit the question of how to prove a program conect for the special case when it is written in a pure functional program-one that is state-less and relies instead on functional composition and recursion as a foundation for its semantics. | CSC141- Introduction to Computer programming Teacher: AHMED MUMTAZ MUSTEHSAN Lecture – 21 Thanks for Lecture Slides: Principles of Programming - NI2005 CSC 141 Introduction to Computer Programming Fundamentals of Characters and Strings In C language characters is either printable or nonprintable including lowercase letters, uppercase letters, decimal digits, special characters and escape sequences. A character is usually stored in the computer as an 8-bits (1 byte) integer. The integer value stored for a character depends on the character set used by the computer on which the program is running. CSC 141 Introduction to Computer Programming There are two commonly used character codes: ASCII (American Standard Code for Information Interchange) EBCDIC (Extended Binary Coded Decimal Interchange Code) Fundamentals of Characters and Strings CSC 141 Introduction to Computer Programming char num = 1 and char num = ‘1’ are not the same. char num = 1 is represented in the computer as 00000001. char num = ‘1’ on the other hand is number 49 according to the ASCII character set. Therefore, it is represented in the computer as 00110001. Difference Between an Integer Digit and a Character Digit CSC 141 Introduction to Computer Programming Example: ASCII character #include void main(void) { char A = 'A'; char Z = 'Z'; char a = 'a'; char z = 'z'; printf("\nASCII value for A is %d\t", A); printf("\nASCII value for Z is %d\t", Z); printf("\nASCII value for a is %d\t", a); printf("\nASCII value for z is %d\t", z); printf("\n"); printf("\n Decimal 65 in ASCII represents %c\t",65); printf("\n Decimal 90 in ASCII represents %c\t",90); printf("\n Decimal 97 in ASCII represents %c\t",97); printf("\n Decimal 122 in ASCII represents %c\t",122); } CSC 141 Introduction to Computer Programming Sample output ASCII value for A is 65 ASCII value for Z is 90 ASCII value for a is 97 ASCII value for z is 122 | CSC141- Introduction to Computer programming Teacher: AHMED MUMTAZ MUSTEHSAN Lecture – 21 Thanks for Lecture Slides: Principles of Programming - NI2005 CSC 141 Introduction to Computer Programming Fundamentals of Characters and Strings In C language characters is either printable or nonprintable including lowercase letters, uppercase letters, decimal digits, special characters and escape sequences. A character is usually stored in the computer as an 8-bits (1 byte) integer. The integer value stored for a character depends on the character set used by the computer on which the program is running. CSC 141 Introduction to Computer Programming There are two commonly used character codes: ASCII (American Standard Code for Information Interchange) EBCDIC (Extended Binary Coded Decimal Interchange Code) Fundamentals of Characters and Strings CSC 141 Introduction to Computer Programming char num = 1 and char num = ‘1’