Fundamentals Flashcards
What does syntax refer to?
Refers to how the vocabulary of a language can be used to form statements
What does semantics refer to?
Defines the meaning of statements
What is stepwise refinement?
When you go through the algorithm and refine the code
Makes it more concrete
Name primitive data types
8 types
- Byte
- Short
- Int
- Long
- Float
- Double
- Chat
- Boolean
How do you declare the constant:
int age = 34;
final int age = 34;
Describe the difference between / and %
- / means divide
- % returns the modulus
modulus = remainder
How is a if / if-else layed out?
if ( condition )
statement1;
else
statement2;
What is a nested statement?
A statement within a statement
What is the order of precedence?
()
* / %
+ -
!
&&
||
What is printed if P is the input?
System.out.print (“Enter a grade (A - E): “);
char grade = Console.getChar();
switch (grade) {
case ‘E’: System.out.print (“V. Poor. “);
case ‘D’: System.out.println (“See the lecturer.”);
break;
case ‘C’: System.out.println (“Could do better.”);
break;
case ‘B’: System.out.println (“Good result.”);
break;
case ‘A’: System.out.println (“Excellent.”);
break;
default: System.out.println (“invalid!”);
}
Invalid
Name 3 data conversions
Assignment conversion
Arithmetic promotion
Casting
Describe assignment conversion
When you widen a variable type to fit in another
Only can be widened, not the other way
What data conversion is this:
byte b = 29;
int i = b;
Assignment converion
What type of data converstion happens automatically?
Arithmetic promotion
What data conversion is this:
int i = 34;
double x = i / 1.2
Arithmetic promotion
int 34 is promoted to double 34.0
In arithmetic promotion
When is the other operand promoted to double?
When the other operand is double
In arithmetic promotion
When is the other operand promoted to int
When both operands are less than an int
In arithmetic promotion
When is the other operand promoted to float?
When one operand is a double & the other isn’t a double
In arithmetic promotion
When is the other operand promoted to long
When one operand is long & the other isnt double | float
In casting
How do we change:
int total = 34, count = 6;
float result = total / count;
so that total & count are float?
float result = (float)total / (float)count;
Put the wanted type in (…) & then the variable follows
What are the names for:
1. ++count
2. count++
Increment Operators
1. Prefix
2. Postfix
What are the names for:
1. –count
2. count–
Dencrement Operators
1. Prefix
2. Postfix
What is result?
What is count?
int count = 5;
int result = count++;
Result = 5
Count = 6
result = count
count + 1
What is result?
What is count?
int count = 5;
int result = ++count;
Result = 6
Count = 6
count + 1
result = count
What is:
num = num + count;
the same as?
num += count;
What are these the same as?
These are called assignment operators
How is a While Loop layed out & how does it work?
Will repeatedly execute until condition is false
When is a While Loop used?
For 0 or more times
How is a For Loop layed out?
When is a For Loop used?
When we know when we want the loop to stop
How is a Do-While Loop layed out & how does it work?
It will execute first & then evaluate if it should execute again
When is a Do-While loop used?
When you want it to execute 1 or more times
How do we declare & instantiate an array with a size of 10?
int[] scores = new int [10]
What are the bounds in an array?
0 to N-1
Make an initialier list from 1-6
int[] score = {1, 2, 3, 4, 5, 6}
