软件工程导论9n.pptVIP

Brooks/Cole, 2003 Chapter 9 ProgrammingLanguages Have a vision of computer language evolution. Distinguish between machine, assembly, and high-level languages. Understand the process of creating and running a program. After reading this chapter, the reader should be able to: OBJECTIVES Distinguish between the different categories of languages:procedural, object-oriented, functional, declarative, and special. Become familiar with elements of the procedural language C. EVOLUTION 9.1 Figure 9-1 Evolution of computer languages00000100 0000000000000000000011000000000000000010 00010110 0000000000000101 10011110 000000000000101110101101 0000000000010010 11011111 000000000001010100000010000000000001011110101101000000000001111010100010000000000010000100000010000000000010010011110100 101011100000000000101011101000100000000000110001000000100000000000110100 0000000000111101 0000000000111101 Program 9.1 Program in machine language 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 The only language understood bya computer is machine language. Note: Entry main, ^mr2 subl2 #12,sp jsb C$MAIN_ARGS movab $CHAR_STRING_CON pushal -8(fp) pushal (r2) calls #2,read pushal -12(fp) pushal 3(r2) calls #2,read mull3 -8(fp),-12(fp),- pushal 6(r2) calls #2,print clrl r0 ret Program 9.2 Program in symbolic language 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 /* This program reads two integer numbers from the keyboard and prints their product. */ #include iostream.h int main (void) { // Local Declarations int number1; int number2; int result; // Statements cin number1; cin number2; result = number1 * number2; cout result; return 0; } // main Program 9.3 Program in C++ language 1 2 3