Control Structures

While and Until

• The while statement continues to loop through a control structure for as long as a control expression evaluates true.
• Example:
  

  while ( expression ) { 
      some_statement; 
      some_statement; 
      some_statement; 
  } 
  

• Like the if versue unless instructions, there is a built in negation for while named until .
• until will continue to loop through the control structure until the control expression evaluates true.
• Example:
  

  until ( expression ) { 
      some_statement; 
      some_statement; 
      some_statement; 
  }