Term
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Definition
| is a storage location in a computer's RAM memory. |
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Term
| What's another name given to variables? |
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Definition
| an identifier, and it must always be given a DATA TYPE. |
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Term
| What do we have to do first prior creating a variable? |
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Definition
| We have to declare it, which means to specify its data type and its name. |
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Term
| What does the the data type tells the computer? |
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Definition
| it tells the OS how many bits of memory will be used to create the variable |
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Term
| what's another name in which "creating variables" is known for? |
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Definition
"Variable binding"
when we declare a variable, we're binding the name of the variable to a particular memory location address. |
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Term
| so..what's Variable binding? |
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Definition
a variable name, or identifier is a reference to a particular memory address.
When we create a variable, we are basically binding the name of it to a particular memory location address. |
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Term
| Mention three forms in which a variable name can start? |
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Definition
a variable name can start with:
- with a letter
- with an underscore
- with a $ sign.
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Term
| What you should never use at the beginning of a variable name? |
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Definition
| Numbers, otherwise it will result in a compile error, you can place numbers at the end of variables name example number 3 |
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Term
| Whats some important info remember about the naming convention? |
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Definition
- variables use regularly cammel back format starting always wiht lower case
- JAVA is CASE-SENTITIVE. so armor would be different to Armor.
- Names can be of any lenght
- you can't use JAVA reserved words such as class, public or else.
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Term
| What's the ROT ( Rule of Thumb) of naming convention? |
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Definition
Variable names must be meaningful. so basically one should be able to infer what it represents by looking at the name. |
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Term
| in Java, where are the program statements contained? |
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Definition
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Term
| by convention how should CLASS NAMES be written? |
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Definition
| they should always starts with UPPER LETTER and then each new word should start with another Upper Letter . this is called TitleCase notation |
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Term
| What does the Data Types tells the OS? |
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Definition
it tells the OS how many bites of memory must be allocated for that variable.
additional your program uses the data type to interpret the data that its store there. |
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Term
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Definition
•A data type is a how a computer language represents the various types of numbers and text characters we use in our physical world internally in the computer’s memory.
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Term
| Mention the 8 primitive Data Types: |
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Definition
- byte
- short
- int
- long
- float
- double
- char
- bolean
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Term
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Definition
oRepresents a single character: ‘a’,’-’, ‘&’, ‘G’, ‘8’ (single quote marks around the character indicate it is a char data type) |
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Term
| What's the int data type: |
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Definition
o to represent a whole number i.e 1,2,3… |
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Term
| What's the double data type: |
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Definition
represents a real or floating point number such as 25.24 |
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Term
| What's the Bolean data type: |
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Definition
| holds either a true or false value. |
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Term
| Mention some Object Data typeS: |
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Definition
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Term
| What's a string data type: |
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Definition
This is actually an object data type that holds a string of alphanumeric characters i.e. “John Doe” or “123 Main Street” |
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Term
| What's a Scanner datat ype: |
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Definition
this is an object data type that we will use to read data that is typed in by the user. |
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Term
| Why are Primitive data types called Primitive? |
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Definition
| Primitives don’t have any methods associated with them |
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Term
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Definition
•A method is just some lines of code that are put in a block and given a name. We can run ( or activate) this method by calling its method name in our code. |
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Term
| How many primitive data types are there in Java? |
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Definition
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Term
| What are the wrapper classes? |
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Definition
| object data type equivalents for each of the primitive data types |
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Term
| There are two main types of Primitive Data types , |
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Definition
- Numeric data types
- non-numeric data types
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Term
| What are the numeric data types? |
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Definition
- byte
- short
- int
- long
- float
- double
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Term
| Which are the non-numeric data types? |
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Definition
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Term
| How much memory does byte store? |
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Definition
| 8 bits , it can also stored negative numbers |
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Term
| how much memory does short can hold? |
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Definition
| Short can hold to 16 bits |
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Term
| how much memory can int stored? |
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Definition
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Term
| how much memory does long can store |
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Definition
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Term
| how much memory does float can store? |
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Definition
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Term
| how much memory does double can store |
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Definition
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Term
| how much memory does char can store |
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Definition
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Term
| how much memory does bolean can store? |
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Definition
| 8 bits, it can only store either true or false |
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Term
| How is a floating point store in a computer? |
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Definition
| as two separate parts, called "mantissa" and "exponent" |
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Term
| What's a constant in Java? |
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Definition
A constant represents a value stored in memory which will not change during the operation of the program.
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Term
| What's the naming convention for Constants? |
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Definition
| ALL must be in Upper Case, if you have more than one word you can use underscores. |
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Term
| How do you declare a constant? |
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Definition
you have to type the word "FINAL" prior the data type and the name of the constant it holds
final double IP = 0.6.
in the case of CONSTANTS you must declare it and initialize it in the same line of code, unlinke VARIABLE where you can declare it and then assigned the value. |
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Term
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Definition
•A. A data literal is an actual data value that appears in a program
•Ex: int age = 5; // 5 is an integer literal
char letter = ‘Z’; // ‘Z’ is a character literal
age = age / 12 + 9;// 12 and 9 are integer literals
double cash = 4.56// 4.56 is a floating point literal |
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Term
| What does the "=" sign represents in java |
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Definition
| zused to assign a data value to a variable in memory, it basically means "gets" |
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Term
| What's another name for the arithmetic operations? |
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Definition
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Term
| What does the % stands for in binary operations? |
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Definition
| it represents the modulus division operator, zThis returns the remainder from a division operation, rather than the quotient. |
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Term
zQ. What is modulus division useful for? |
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Definition
zone common use is to determine if a value is odd or even by doing a modulus division by 2 on the test value.
The answer of a modulus division operation is the REMAINDER value from a regular division operation. |
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Term
| What's the operator precedence in Java? |
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Definition
is the order in which the bynary operations are performed similar to BEDMAS,
1ST - BRAKETS
2ND - /, %, *
3RD - + -
4TH = |
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Term
| How can you test if two values are the same? |
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Definition
By using the equality operator ==
if(amount1 == amount2)
system.out.println("They are equal") |
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Term
| How can we test if they are not equal? |
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Definition
using the !=
if(amount1 != amount2)
System.out.print(“Values not equal”); |
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Term
| What are the Unary Operators? |
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Definition
basically the + or - values.
a numeric value is always positive by default so there's no need to |
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Term
| What the increment variable and how it's represented |
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Definition
it is represented as ++
and basically it adds "one" to another variable |
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Term
| What the decrement variable and how it's represented |
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Definition
it's represented as --
it substracts "one" from a variable |
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Term
| What does TypeCasting stands for? |
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Definition
zConverts a value of one data type into a value of another data type (T!)
zNOTE: it is the value stored in the variable that gets converted, and not the variable itself. |
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