chapter 9

Question 1

if you are trying to store words or sentences in Java what is it that you need?

Answer 1

If you’re trying to store words or sentences (not just single letters), then you need to use something called a String.

Question 2

what is it you need to choose between 2 different choices in a java program?

Answer 2

in order to choose between to options in a java program you will need an if statement

Question 3

what is the basic format for creating an if statement?

Answer 3

if(Condition){
SomeStatements
} else{
OtherStatements
}

Question 4

what is an “if clause” and an “else clause”?

Answer 4

the “if clause” pertains to the statements written for the “if statements” and the else clause corresponds to the other statements for the else statements.

Question 5

what symbol must an if and else clause be in between of?

Answer 5

whether you are writing statements for the “if clause” or the “else clause” you must put the statements within parentheses followed by a semicolon

Question 6

what 2 types of errors often occur without warning when writing if statements in a java program?

Answer 6

using a semicolon immediately after the word else will compile without errors but the statements will always be executed whether the condition is true or false

missing curly braces will compile without errors but the program’s run may not do what you expect it to do so make sure you add curly braces

Question 7

how do you write an if statement’s skeletal outline and how is typing the if statement’s skeletal outline help you with writing your code?

Answer 7

if () {
} else{
}
when you apply this kind of thinking to a compound statement, it’s harder to make a mistake. just write this first and then fill in the blanks.

Question 8

when using the random method, why must you add a + 1 to the random variable (10) if your intent is to have a range of 1 to 10 ?

Answer 8

you must add 1 if you want to get that 1 to 10 range because if not it will be a range of 0 to 9

Question 9

what is “Random” in the Java API?

Answer 9

it is a class which stores methods to select a random variable and it’s not limited to just numbers but strings and characters as well.

Question 10

why would a random number created by computers not be truly considered a random number? what are these random numbers that computers generate be called instead?

Answer 10

a computer has a pattern to create randomly generated numbers but these numbers arent truly random if you try to create a random number using a computer. these randomly created numbers are called pseudo random numbers

Question 11

why is it important to indent your code?

Answer 11

if you don’t indent your statements in some logical fashion, niether you nor anyone else can make sense of your code. indenting helps you the user and the programmer to understand the code.

Question 12

since indentation is important in writing code, what is an easy way to deal with creating neatly indented code?

Answer 12

Eclipse has a feature that allows it to automatically indent your code.

Question 13

what happens if you dont write an else clause for your if statement?

Answer 13

then if the if clause is activated it will display the if statement’s condition but if not it stays blank and continues with the rest of the code if there is any.

Question 14

how do you compare 2 numbers in an if statement’s statement?

Answer 14

you always use a double equal sign.

Question 15

why do you need a double equal sign to compare 2 numbers instead of just 1 equal sign?

Answer 15

because 1 equal sign does assignment while a double equal sign does comparisons

Question 16

how would you display the random number after an if statement without an else clause? and why?

Answer 16

you would write a println outside of the if statement after the if statement because if you wrote the println within the parentheses of the if statement, then the random number would only display if the random number is activated instead of displaying the random number everytime you run the program.

Question 17

how many statements can you put inside of an if statement?

Answer 17

only one for each of the if and else clause.

Question 18

in what way can you fit more than 1 statement within the if and else clause?

Answer 18

make sure to use curly braces where it is needed as they act like kind of a block, allowing you to add more than 1 statement for both the if and else clause.

Question 19

how does a block of code containing 2 statements within the if and else clause behave?

Answer 19

it acts as if it is a single statement.

Question 20

what is a block statement?

Answer 20

it is a couple of statements within a bracket considered one large statement.

Question 21

what part of a program is used to abbreviate code?

Answer 21

the ability to abbreviate things is called static import