Java In 21 Days Day 4

Front 1

Arrays definition?

Back 1

Arrays are a way to collect similar primitive types or similar classes together.

Front 2

Steps to declare arrays?

Back 2

1) Declare a variable to hold Array
2) Declare a new array object and assign it to the array variable.
3) Store information in the array

Front 3

How to Declare a variable to hold Array?

Back 3

Use [ ] to declare array variable and differentiate from a regular variable.
ex: String [ ] request ;

Front 4

How to Declare a new array object?

Back 4

1) Use the 'new' operator
2) Initialize the content of the array
ex: Integer [ ] requests = new integer [3] ;

Front 5

How to Store information in the array:

Back 5

ex: Integer [ ] testScore = new integer [41]
testScore [40] = 920 ;
We set the 41st slot in the array to a value of 920.Value is checked against array index range.

Front 6

when Changing Array object value do we copy that value ????

Back 6

When assigning a value to an array object we are only referencing and not copying that value

Front 7

Does java support multi-dimensional arrays???
If not what does it support then??

Back 7

No, but Java supports making an array of arrays.

Front 8

What are block statements?

Back 8

Are statements bounded by braces { } and executed within these boundaries.

Front 9

if Conditional statement definition?
When is it used?

Back 9

Is a decision making mechanism, it executed only when a certain condition has been met (Boolean condition), bounded by { }

Front 10

Switch conditional statement definition?
When is it used?

Back 10

The practice of testing a variable against a value, if it does not match it ,it will be tested against another one until a match is found.

Front 11

Switch Example

Back 11

switch variableName {
case 'A':
system.out.println ("");
break
case 'b': then have default:" to exit"

Front 12

for Loops definition and when to use?

Back 12

Used to repeat a statement until a condition is met

Front 13

example of a for loop

Back 13

for (initialization ; test ;increment){
Statement;
}

Front 14

while and do loops

Back 14

for and while and do loops are similar choosing which one depends on programing style.

Front 15

do-while Loop?

Back 15

Similar to while Loop but the condition is executed at least once before testing for true or false.

Front 16

how to break out of a Loop

Back 16

using the break command when the condition is fulfilled.

Front 17

Label Loops?

Back 17

when loops has a label telling them where to start executing conditions again. Could be used to execute out of the loop if needed.they are marked with a colon :

Front 18

Example Labeled Loop

Back 18

out:
for (int i = 0 ; i<10 ; i++){
break out;
}

Front 19

Conditional Statement Def.?

Back 19

Is an expression that returns a Boolean value that in return chooses a value based on the true or false.

Front 20

example of a Conditional Statement?

Back 20

int ourBestScore = myScore > yourScore ? myScore : yourScore

If true will return myScore if false will return your Score