# Chapter 3 - Literals

Literals are data used for representing fixed values or constant variables that cannot be changed or modified. They can be used directly in the code. For example:

``const int = 10``

The 10 represents the value 10, not a variable named 10.

## Integersโ

An integer is known as a numeric literal without a fraction or an exponent. In C programming there are three different types of integer literals:

• Decimal
• Eg: 0, -10, 22
• Octal (base 8 system)
• Eg: 021, 077, 033
• Hexadecimal (base 16)
• Eg: 0x7f, 0x2a, 0x521

Example: change 78 to octal

``Divide 78 by 8 until 078 รท 8 = 9 R 69 รท 8 = 1 R 11 รท 8 = 0 R 1The output will be 116``

(Reminder: the remainder from the first division should be in the ones digit)

What the code should look like

``void setup(){    Serial.begin(9600);    Serial.println(78, OCT);}void loop(){}``

Serial Monitor

``116``

# YOU TRY!

In serial.print() enter a number then a comma and OCT. See what the output is in the serial monitor.

Eg: serial.print(78, OCT); should print out 116

## Floating-Point Literalsโ

A floating-point literal isa numeric literal that contains a decimal point. It is usually stored in either a decimal form or an exponent form.

Example:

Valid EntriesInvalid Entires
-22.5123E
0.000342353554

## Character Literalsโ

• Character literals are used to store a single character within a single quote (โxโ). To store multiple characters, you will use a character array instead.
Valid EntriesInvalid Entries
'a''Programming'
'F''Flower'
'3''integer'
',''sign'

## String Literalsโ

String literals are similar to character literals, the difference is that string literals are capable of storing multiple characters enclosed in double quotation marks (โbookโ).

Valid EntriesInvalid Entries
"myAge"'True'
"remainingNumber"'false'
"percentYield"'Keys'

## What are Literals used for?โ

Using a literal, you can use the variable name rather than rewriting the value again and again.

Example:

Instead of using 11

``void setup(){    pinMode(11, OUTPUT);}void loop(){    digitalWrite(11, HIGH);    delay(1000);    digitalWrite(11, LOW);    delay(1000);}``

Use a declared integer (Eg. int LED = 11)

``int LED = 11; //<---Declare an integervoid setup(){    pinMode(LED), OUTPUT);}void loop(){    digitalWrite(LED), HIGH);    delay(1000);    digitalWrite(LED, LOW);    delay(1000);}``

## Escape Sequencesโ

Some characters/shortcuts that we used cannot be typed in C programming. For example, enter (for a new line), and tab (for indent). Escape sequences are used to replace of these actions.

Escape SequencesCharacters
\fForm Feed
\nNewline
\rReturn
\tHorizontal Tab
\vVertical Tab
\Backslash
\โSingle Quotation mark
\โDouble Quotation mark
\?Question mark
\0Null Character