Incremental Coding

1
Incremental Coding

• Incremental coding is good!
• Uses divide and conquer to minimize problem scope
• Helps testing tremendously!
• So what is it?
• It is a methodology for writing your program
• Two types
• Top down
• Bottom up

2
Incremental Coding Top Down

• The top down approach begins with the general and
  works towards the specifics
• Start with a skeleton class
• Add small details a little at a time
• Test after each addition!

3
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2
• // this is the constructor
• public Example(int first, int second)
• data1 first
• data2 second

// this is another instance method // this
method computes a fraction of data1 public
double getDataFraction(double fraction) double
result result fraction data1 return
result // this is the main method public
static void main(String args) Example e1
new Example(1,2) Example e2 new
Example(3,4) int x e1.getData1() int y
e2.data2 int z e1.data2 e2.getData1() d
ouble f e2.getDataFraction(0.4) //end
of Example class
4
Incremental Coding

• /
  
• Title Example.java
• Files Example.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example

//end of Example class
5
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2

//end of Example
class
6
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2
• // this is the constructor
• public Example(int first, int second)
• // code will go here

// this is another instance method // this
method computes a fraction of data1 public
double getDataFraction(double fraction) //
code will go here // this is the main
method public static void main(String
args) // code will go here //end
of Example class
7
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2
• // this is the constructor
• public Example(int first, int second)
• // code will go here

// this is another instance method // this
method computes a fraction of data1 public
double getDataFraction(double fraction) //
code will go here // this is the main
method public static void main(String
args) // code will go here //end
of Example class
8
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2
• // this is the constructor
• public Example(int first, int second)
• data1 first
• data2 second

// this is another instance method // this
method computes a fraction of data1 public
double getDataFraction(double fraction) //
code will go here // this is the main
method public static void main(String
args) // code will go here //end
of Example class
9
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2
• // this is the constructor
• public Example(int first, int second)
• data1 first
• data2 second

// this is another instance method // this
method computes a fraction of data1 public
double getDataFraction(double fraction) double
result result fraction data1 return
result // this is the main method public
static void main(String args) // code
will go here //end of Example
class
10
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2
• // this is the constructor
• public Example(int first, int second)
• data1 first
• data2 second

// this is another instance method // this
method computes a fraction of data1 public
double getDataFraction(double fraction) double
result result fraction data1 return
result // this is the main method public
static void main(String args) Example e1
new Example(1,2) Example e2 new
Example(3,4) int x e1.getData1() int y
e2.data2 int z e1.data2 e2.getData1() d
ouble f e2.getDataFraction(0.4) //end
of Example class
11
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2
• // this is the constructor
• public Example(int first, int second)
• data1 first
• data2 second

// this is another instance method // this
method computes a fraction of data1 public
double getDataFraction(double fraction) double
result result fraction data1 return
result // this is the main method public
static void main(String args) Example e1
new Example(1,2) Example e2 new
Example(3,4) int x e1.getData1() int y
e2.data2 int z e1.data2 e2.getData1() d
ouble f e2.getDataFraction(0.4) //end
of Example class
12
Incremental Coding Bottom up

• The Bottom up approach begins with specific
  details slowly combines them into the program
• Start with a skeleton class
• Code individual functional parts of the program
• Slowly combine functional parts
• Test after each combination!

13
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example

//end of Example
class
14
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example

// this is the main method public static
void main(String args) Example e1 new
Example(1,2) Example e2 new
Example(3,4) //end of Example
class
15
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // this is the constructor
• public Example(int first, int second)
• data1 first
• data2 second

// this is the main method public
static void main(String args) Example e1
new Example(1,2) Example e2 new
Example(3,4) //end of Example
class
16
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2
• // this is the constructor
• public Example(int first, int second)
• data1 first
• data2 second

// this is the main method public
static void main(String args) Example e1
new Example(1,2) Example e2 new
Example(3,4) //end of Example
class
17
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2
• // this is the constructor
• public Example(int first, int second)
• data1 first
• data2 second

// this is the main method public static
void main(String args) Example e1 new
Example(1,2) Example e2 new
Example(3,4) int x e1.getData1()
//end of Example class
18
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2
• // this is the constructor
• public Example(int first, int second)
• data1 first
• data2 second

// this is the main method public static
void main(String args) Example e1 new
Example(1,2) Example e2 new
Example(3,4) int x e1.getData1()
//end of Example class
19
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2
• // this is the constructor
• public Example(int first, int second)
• data1 first
• data2 second

// this is the main method public static
void main(String args) Example e1 new
Example(1,2) Example e2 new
Example(3,4) int x e1.getData1() int y
e2.data2 //end of Example class
20
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2
• // this is the constructor
• public Example(int first, int second)
• data1 first
• data2 second

// this is the main method public static
void main(String args) Example e1 new
Example(1,2) Example e2 new
Example(3,4) int x e1.getData1() int y
e2.data2 int z e1.data2 e2.getData1()
//end of Example class
21
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2
• // this is the constructor
• public Example(int first, int second)
• data1 first
• data2 second

// this is the main method public static
void main(String args) Example e1 new
Example(1,2) Example e2 new
Example(3,4) int x e1.getData1() int y
e2.data2 int z e1.data2 e2.getData1() d
ouble f e2.getDataFraction(0.4) //end
of Example class
22
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2
• // this is the constructor
• public Example(int first, int second)
• data1 first
• data2 second

// this is another instance method // this
method computes a fraction of data1 public
double getDataFraction(double fraction) double
result result fraction data1 return
result // this is the main method public
static void main(String args) Example e1
new Example(1,2) Example e2 new
Example(3,4) int x e1.getData1() int y
e2.data2 int z e1.data2 e2.getData1() d
ouble f e2.getDataFraction(0.4) //end
of Example class
23
Incremental Coding

• /
  
• Title Card.java
• Files Card.java
• Author Peter McClone
• CS Login mc-clone
• 
  /
• // no import statements
• public class Example
• // these are instance variables
• private int data1
• public int data2
• // this is the constructor
• public Example(int first, int second)
• data1 first
• data2 second

// this is another instance method // this
method computes a fraction of data1 public
double getDataFraction(double fraction) double
result result fraction data1 return
result // this is the main method public
static void main(String args) Example e1
new Example(1,2) Example e2 new
Example(3,4) int x e1.getData1() int y
e2.data2 int z e1.data2 e2.getData1() d
ouble f e2.getDataFraction(0.4) //end
of Example class
24
Incremental Coding

• Questions????