Basics

Question 1

They perform operations on numbers, strings, and other values

Answer 1

literals

Question 2

(5) basic literals

Answer 2

integers, characters, strings, boolean, and arrays

Question 3

numbers

Answer 3

integer or int

Question 4

A single character can represent a digit, a letter, or another symbol

Answer 4

character or char

Question 5

To write a single character, we wrap in

Answer 5

single quotes
NOTE: Character literals can represent alphabet letters, digits from ‘0’ to ‘9’, whitespaces (‘ ‘), or some other symbols

incorrect: ‘abc’, ‘543’

Question 6

text information

Answer 6

string

Question 7

To write strings, we wrap characters in

Answer 7

double quotes
NOTE: “text”, “I want to learn Kotlin”, “123456”, “e-mail@gmail.com”

A string can also contain just one single character, like “A”. Do not confuse it with the character ‘A’, which is not a string.

Question 8

(6) relational operators

Answer 8

== — equal to X

!= — not equal to X

> — greater than X

> = — greater than or equal to X

< — less than X

<= — less than or equal to X

NOTE: Boolean value (true or false)

Question 9

a way of writing numbers using only two digits, 0 and 1

Answer 9

binary numeral system or base-2 numeral system

Question 10

when a digit reaches 1, the next number resets this digit to 0 and causes the digit to the left to raise

Answer 10

binary counting

Question 11

work with binary numbers of a fixed length

Answer 11

zero padding

NOTE:
- triads: 000, 001, 010, and so on;

• tetrads: 0110, 0111, and so on;
• 8-digit numbers: 00000000, 01010101, and so on.

Question 12

An 8-digit binary number
NOTE: 256 possible values from 0 to 255

Answer 12

byte

Question 13

a way of storing information

Answer 13

binary code

Question 14

each character in the text string represented by a 7-digit binary number

Answer 14

ASCII code
(American Standard Code for Information Interchange)

Question 15

Red, Green, Blue
NOTE: color encoding system stores 3 binary values

Answer 15

RGB

Question 16

a standard for encoding and representing text

Answer 16

Unicode

Question 17

every symbol corresponds to a number

Answer 17

code point

Question 18

Unicode is represented with

Answer 18

U+
NOTE: Capital Letter Q is U+0051

Question 19

(6) escape or control sequences

Answer 19

‘\n’ is the newline character;

‘\t’ is the tab character;

‘\r’ is the carriage return character;

’\’ is the backslash character itself;

’'’ is the single quote mark;

’"’ is the double quote mark.

Question 20

isDigit()

Answer 20

returns true if the given character represents a digit (‘1’, ‘2’, etc); otherwise, false

Question 21

isLetter()

Answer 21

returns true if the given character represents a letter (‘a’, ‘B’, ‘m’, etc); otherwise, false

Question 22

isLetterOrDigit()

Answer 22

returns true if the given character represents a letter or a digit; otherwise, false

Question 23

isWhitespace()

Answer 23

returns true if the given character represents a whitespace (‘ ‘, or ‘\t’, or ‘\n’); otherwise, false

Question 24

isUpperCase()

Answer 24

returns true if the given character is an uppercase character; otherwise, false

Question 25

isLowerCase()

Answer 25

returns true if the given character is a lowercase character; otherwise, false

Question 26

uppercaseChar()

Answer 26

returns the uppercase form of the given character

Question 27

uppercase()

Answer 27

returns a String with the uppercase form of the given character

Question 28

lowercaseChar()

Answer 28

returns the lowercase form of the given character

Question 29

lowercase()

Answer 29

returns a String with the lowercase form of the given character