Evolution of the Variable

• Machine Lanaguage
  • Absolute addresses
  • Hexadecimal values
• Assembly Language
  • Names instead of addresses
  • Data type determined by element size

    .data
    initials db 'X', 'Y', 'Z'
    pay dw 4 dup(?)
    name db 'String'
    count dw 100, 200, 300
  

• High Level Languages
  • Names
  • Data type determined by application

   int count;
   float pay_rate;
   char initial;