Dart

Question 1

What is required for a dart program

Answer 1

A main method

Question 2

How should variables be named in Dart

Answer 2

Camel Case

Question 3

How do you accomplish string interpolation in Dart

Answer 3

$variableName

Question 4

How can you interpolate an expression in Dart?

Answer 4

${expression}

Question 5

How do you escape special characters

Answer 5

/

Question 6

How do you print a string without having to escape special characters?

Answer 6

r”stuff” - raw string

Question 7

What is multi line string syntax?

Answer 7

”"”stuff”””

Question 8

How do you do integer division?

Answer 8

~/

Question 9

What effect does the prefix and postfix operators have?

Answer 9

Prefix (++x) adds and then assigns the value of x, postfix (x++) assigns the value of x and then adds

Question 10

How do you write a hex number?

Answer 10

0x(number)

Question 11

How can you print numbers in binary or hex?

Answer 11

(string).toRadixString((base))

Question 12

Expressions

Answer 12

Hold a value at runtime

Question 13

Statements

Answer 13

Do not hold a value at runtime

Question 14

When is var used?

Answer 14

To declare variables that can be used more than once

Question 15

When is final used?

Answer 15

For read only variables

Question 16

When is const used?

Answer 16

For compile time constants

Question 17

When is dynamic used?

Answer 17

When you want to be able to change the type of the variable

Question 18

What are the collections in Dart

Answer 18

Lists, sets and Maps

Question 19

What’s special about sets?

Answer 19

They only hold unique values

Question 20

What are maps like?

Answer 20

Dictionaries

Question 21

How can I read a file?

Answer 21

final lines = File(inputFile).readAsLinesSync();

Question 22

What does a question mark after a variable mean?

Answer 22

It’s nullable

Question 23

What is the if-null operator?

Answer 23

??, it assigns whatever is after it if the variable is null

Question 24

What does this do? maybeNull ??= 0

Answer 24

Assigns 0 to maybeNull if it’s null

Question 25

How do positional arguments work?

Answer 25

Put the arguments in the method in {} and pass name: value when calling it

Question 26

How can you implement optional positional arguments?

Answer 26

Put them in []

Question 27

What is => for?

Answer 27

Fat arrow notation, for functions that only have one line remove {} and return

Question 28

What is an alias?

Answer 28

A name given to a function type so it can be reused

Question 29

rHow does forEach work?

Answer 29

list.forEach((x) => print(x));

Question 30

What is map for?

Answer 30

Take a collection, perform some transformation on it and return a new collection

Question 31

What does the where method do?

Answer 31

Performs filtering

Question 32

What is the reduce method for?

Answer 32

Combining elements in a collection

Question 33

What is an initializer list in dart?

Answer 33

It assigns variables passed into the constructor to member variables and is started after the constructor with a colon

Question 34

What are getters also known as?

Answer 34

Computed variables

Question 35

What are class variables known as?

Answer 35

Stored variables