Developing Software: Introduction Flashcards
What is a boolean data type used for?
Boolean data type is used to store a true or false value
it is used to store the result of equations which use relational operators == , != , > , < , >= , <=.
Name the three types of errors!
Syntax Errors
Logical Errors
Runtime Errors
What is a Syntax error?
Syntax errors: Syntax errors represent grammar errors in the use of the programming language.
Examples:
Misspelled variable and function names
Missing semicolons
What is a Logical error?
Logical errors: A statement with logical error may produce unexpected and wrong results in the program. Logic errors are the hardest to find and fix.
Examples:
Multiplying when you should be dividing
Displaying the wrong message
What is a Runtime error?
Runtime errors A type of error that occurs during the execution of a program is known as run-time error
Trying to divide by a variable that contains a value of zero
Trying to open a file that does not exist
What is the objective of testing?
Executing a program with the intent of finding errors/faults.
To check if the system meets the requirements and be executed successfully in the Intended environment.
To check if the system is “ Fit for purpose”.
Name some good programming practice
Proper naming conventions - camel case and using underscores
Aligning matching curly brackets together in a straight line.
Indentation and White Space
Internal Commentary - clarifying complex code for idiots, locations - top of file ( author, date, when it was edited and how etc ), above methods, above complex code.
Indentations
Following companies style guide
Why should you bother with good coding practice?
To make it look fabulous af
Also programmers build on top of each others code all the time, more time is spent on maintenance than writing new code. You shouldn’t waste time deciphering what a method does, just read its comment.
What is a variable?
Holds data/information while the program is running
These storage locations can be referred to by their names
What are the properties of a variable?
Name - reference to the location -cannot be changed
Value - the information that is stored - can be changed during program execution, hence the name “variable”
Data Type - the type of information that can be stored - cannot be changed
What is a global variable?
Global variable
Can be read or changed from any task or function in your code.
Its value can be seen/read globally.
What is a local variable?
Local variable
Belongs only to the task or function in which it was created
Value can only be read or changed from within that task or function
Value can only be seen/read locally
Generally the type of variable you’ll want to use
What is the scope of a variable ?
Variables can have either a “global” or a “local” scope.
This relates to how and by what the variable is able to be used by.
Global variables can be used/accessed/changed anywhere in the program.
Local variables can only be used/accessed/changed within the method in which they were created in.
What is the size and range of the byte data type?
8 Bits
-128 to 127
What is the size and range of the short data type?
16 Bits
-32,768 to 32,767
What is the size and range of the int data type?
32 bits
-2,147,483,648 to 2,147,483,647
aka 2 to the 32 minus 1
(this value is split in half by the negative and positive side equally)
What is the size and range of the long data type?
64 bits -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 fuck remembering that shit aka 2 to the power of 64 minus 1. (this value is split in half by the negative and positive side equally)
