Attempt every question
You get marks for every correct bit even if you don't fully understand the question e.g. input data or print.
Read all questions carefully.. take your time ( unless you're definitely running out!).
The most common reason to lose lots of marks is to slightly misunderstand the question.
Input and Output
Print("hello")
Name = input( "Please enter your name")
Name = input( "Please enter your name")
Data Types
String - word.
Char - one letter.
Int - whole number.
Double / Float / Real - number with decimal places.
Bool - true or false.
If you are asked to choose a data type and give a reason - check the scenario and include the keywords in your answer. For example don't write "it's a whole number" write "words in a book must be a whole number."
Char - one letter.
Int - whole number.
Double / Float / Real - number with decimal places.
Bool - true or false.
If you are asked to choose a data type and give a reason - check the scenario and include the keywords in your answer. For example don't write "it's a whole number" write "words in a book must be a whole number."
Creating a variable
int num = 9;
string Surname = "Simpson";
char initial = 'B';
bool hasChildren = false;
double AccountBalanace = 9.99
string Surname = "Simpson";
char initial = 'B';
bool hasChildren = false;
double AccountBalanace = 9.99
Sequence
Just means lines of code one after the other e.g. print("hello")
Selection - IF and Switch
if( age > 12)
{
// code here
}
{
// code here
}
Iteration - means Loops! |
If you don't understand what to do with the loop. You'll still get at least one mark for writing out a loop!
|
Count Controlled - Loops a set number of times
// Loop 10 times - will display the numbers 0 to 9
for( int x = 0; x < 10; x++) { print( x) } |
If you can't remember all parts you can try..
for( x in 1 to 10) { print(x) } a kind examiner will probably still give you the marks! |
Condition Controlled - Loops while the condition results in true
// will continue to loop until the password entered is "abc"
string password = ""; while( password != "abc" ) { password = input("please enter password"); } |
// will ask first and then check if the password is "abc". If it isn't, it will loop.
string password = ""; do { password = input("please enter password"); } while( password !="abc) you may also see on questions: repeat { // code here } until ( // condition here) |
Strings
SubString gets part of the string:
string name = "Bart"
// start at 0 and get 2 letters..
string newStr = name.SubString(0,2)
print( newStr) // will print "Ba"
string name = "Bart"
// start at 0 and get 2 letters..
string newStr = name.SubString(0,2)
print( newStr) // will print "Ba"
Upper converts into upper case ( capital letters)
string name = "Bart" string newStr = name.Upper() print( newStr) // will print "BART" |
Upper converts into lower case:
string name = "Bart" string newStr = name.Lower() print( newStr) // will print "bart" |
Functions and Procedures
Functions and Procedures are both sub programs. However, there is a slight difference..
A procedure does something but doesn't return ( pass out) any data
public void DoSomething( )
{
// code here
}
{
// code here
}
A function does something but also returns data. Void is replaced with the data type of the data being returned
public string GreetMe( )
{
return "hello"
}
public int GiveMeANumber( )
{
// generates a random number
return Random.Next( )
}
public string GreetMe( )
{
return "hello"
}
public int GiveMeANumber( )
{
// generates a random number
return Random.Next( )
}
Calling a function
You must store the data returned in a new variable.
// call the function and store the result in val:
int val = GiveMeANumber( );
// call the function and store the result in val:
int val = GiveMeANumber( );
Functions with Parameters
Parameters pass data in:
// display the number passed in.. public void DisplayNum( int num) { print(num) } |
Multiple Parameters
Put commas in between multiple parameters // display the result of adding the two numbers passed in.. public void AddNums( int FirstNum, int SecondNum) { int result = FirstNum + SecondNum print(result) } |
Calling a function with parameters
// call ( use) the function by stating its name and passing in the values you want to use..
DisplayNum( 99) |
AddNums(3,4)
|
Hint for Exam Questions on Functions
If the question says use or call. Don't create a function, call the one that already exists ( either in the question or if you already made it).
File Handling
Remember Exam File Handling is simpler.
If you are asked to save data:
If you are asked to save data:
- Open the file.
- Save the data.
- Close the file.
Sorting
Bubble Sort - Bubbles up to the end.
Insertion Sort - Inserts to the beginning.
Merge Sort - Repeatedly splits array into half until you have one element ( item). Then merges back to 2, then to 4, then to 8. Quick but takes lots of space with many arrays.
Insertion Sort - Inserts to the beginning.
Merge Sort - Repeatedly splits array into half until you have one element ( item). Then merges back to 2, then to 4, then to 8. Quick but takes lots of space with many arrays.
IDEs
Visual Studio is an IDE! You can
- breakpoint
- easily edit your code
- code is highlighted in different colours e.g. parts of the language are in blue.
- you can see all your files together
Programming Languages
High Level -easier to read but slower to run ( like C#).
Low Level - harder to read but quicker to run ( like assembly).
Low Level - harder to read but quicker to run ( like assembly).
Testing
Types of Testing:
- Iterative - as we go along
- Final
- Normal
- Erroneous
- Boundary