Sub Routine - ChoDragon9/posts GitHub Wiki

Sub Routine Flow

• Sub Routine remember Return point

const routineA = _ => 1
const routineB = _ => 2

const a = routineA()
console.log(a) // 1
const b = routineB()
console.log(b) // 2

[Main Flow]
  => [Routine A] => [Routine A Sub Flow]
  <= [Routine A Return]
  => [Routine B] => [Routine B Sub Flow]
  <= [Routine B Return]

Communicate with routine

• Main routine communicate by Arguments with Sub routine
• Sub routine communicate by Return with Main routine

[Main Flow]
  => [Routine A Arguments] => [Routine A Sub Flow]
  <= [Routine A Return]

Sub Routine in Sub Routine

• When Routine have Sub Routine, Routine have to remember Keep Point
• Keep Point is called Call Stack
• When Sub Routine return, Call Stack is free

[Main Flow]
  => [Routine A]
      => [Routine B]
      <= [Routine B Return]
  = [Free Keep Point of Routine B]
  <= [Routine A Return]

Structured Design

• Larry Constantine - Structured Design
• High Cohesion, Low Coupling