Program Construction

Program Construction

1. Translators

   • computers can only use binary machine code
   • It has to be converted into the computers language
   • We use the term "translators" for all types of software that converts code
   • Compliers,interpreters and assemblers are all types of translators

2. Assemblers

   • Assembly language is a low- level programming language
   • An assembler is a program that converts assembly language program into executable code that the processor can execute
   • An opcode is short for "operation code" and is a single instruction that can be executed by the CPU

3. Compilers

   • A compiler translates a source code program into machine code
   • Lexical analysis
     • Removes unneeded spaces
     • Replaces keywords and constants with "tokens"
     • Creates a symbol table which shows the addresses of variables, labels and subroutines
   • syntax analysis
     • The code is checked for any spelling and grammar mistakes
     • If syntax errors are found, an error message is produced