Conditionals

Like other programming languages, conditionals are supported in Notes Calculator.

The first two fundamental values you need to know are true and false. These values are used to represent the truthiness of a condition.

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Calculation example

Calculation	Result
1true	true
2false	false

Comparison Operators

Comparison operators are used to compare two values and return a boolean result (true or false).

Operator	Name	Behaviour
==	Equal to	Returns true if left value and right value are equal
!=	Not equal to	Returns true if left value and right value are not equal
>	Greater than	Returns true if the left value is greater than the right value
<	Less than	Returns true if the left value is less than the right value
>=	Greater than or equal to	Returns true if the left value is greater than or equal to the right value
<=	Less than or equal to	Returns true if the left value is less than or equal to the right value

For example:

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Calculation example

Calculation	Result
11 == 1	true
21 != 2	true
31 < 2	true
42 < 1	false
51 >= 1	true
62 <= 2	true

Logical Operators

Logical operators are used to combine multiple conditions. The result is true if the combined condition

Operator	Name	Behaviour
&& or and	and	Returns true if both conditions are true
|| or or	or	Returns true if at least one condition is true
not	not	Flips a condition: true becomes false and back
xor	exclusive or	Returns true if exactly one of the two conditions is true

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Calculation example

Calculation	Result
11 == 1 && 2 == 2	true
21 == 1 and 2 != 2	false
31 == 1 || 2 != 2	true
41 != 1 or 2 != 2	false

not and xor are case-insensitive, and a plain number works as a condition too: zero is false, anything else is true.

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Calculation example

Calculation	Result
1not false	true
2not true and false	false
3true xor false	true
4true xor true	false
55 and 3	true
65 and 0	false

not binds looser than xor, so put it in brackets to use it as an xor operand: true xor (not false).

The integer xor is unchanged: with whole numbers it still works bit by bit:

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Calculation example

Calculation	Result
15 xor 3	6

if, else, then

The if, else, and then keywords are used to control the flow of execution based on conditions.

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Calculation example

Calculation	Result
1earnings = $25k	$25,000
2if earnings > $30k then tax = 15% else tax = 5%	5%
3earnings x tax	$1,250

Conditions can be variables, comparisons, or combinations of them:

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Calculation example

Calculation	Result
1x = 5	5
2if x > 1 and x < 9 then 1 else 2	1
3if 0 then 1 else 2	2
4if false then 7	false

Hours worked on a normal day:

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Calculation example

Calculation	Result
1weekend = false	false
2if not weekend then 8 else 0	8

With no else, a false condition gives false.

The ? : shorthand

condition ? value if true : value if false does the same job in fewer characters:

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Calculation example

Calculation	Result
1true ? 1 : 0	1
25 > 3 ? 10 : 20	10
3not false ? 1 : 0	1
4true xor false ? 10 : 20	10

Conditionals inside a calculation

Wrap a conditional in brackets and it behaves like any other value:

A member discount, for example:

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Calculation example

Calculation	Result
1member = true	true
2$100 x (if member then 0.9 else 1)	$90
3$100 x (member ? 0.9 : 1)	$90
42 * (5 > 3 ? 10 : 20)	20

The branches keep their own type, so a conditional can return money or a unit amount, not just a plain number:

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Calculation example

Calculation	Result
1express = true	true
2express ? 15€ : 5€	€15
3checked = false	false
4if checked then 23 kg else 8 kg	8 kg

When a condition has no answer

If the condition itself can’t be worked out, such as an empty total or something like 0/0, the line shows no answer at all rather than quietly taking the false branch:

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Calculation example

Calculation	Result
1total ? 1 : 2
20/0 ? 1 : 2

Declare a variable using a conditional

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Calculation example

Calculation	Result
1income = $40k	$40,000
2expenses = $25k	$25,000
3profitable = true if income > expenses	true
4insolvent = false unless expenses > income	false