1. Authoring

Content

• The content editor can be used as MS Word.
• The symbol * signify a variable. e.g. *x will be substituted by the value of x from code.
• LaTex is used in equation objects. See KaTeX for a list of supported syntax.
• Answer options must be listed as bullet points. The first option must be the correct answer. e.g.
  • I only
  • I and II only
  • I and III only
  • I, II and III only

Populate

• All variables must be defined here, e.g. x = 1.
• All alphabets (a-z,A-Z) are pre-declared as variables. Once defined, their values can be substituted in the content.
• Each line should end with a semicolon ;.

Validate

• All variables validation should be done here, e.g. x < 10.
• Must return a single Boolean expression, no matter how complex.
• One line should contain only one condition for clarity.
• If no validation is needed, just left it blank.
• Some common logical operators:
  • and: x && y
  • or: x || y
  • not: !x
  • equal: x === y
  • unequal: x !== y

Processing

• This is for manipulating the content as html strings.
  e.g. question = question.replaceAll('3','three').
• Can access the question html string as question.
• Can access the solution html string as solution.
• Preprocess code are executed before substituting the variables.
• Postprocess code are executed after substituting the variables.

Code Execution Flow

1. Run populate to define to variables.
2. Run validate.
   If failed, populate again and again until validation passed.
   The execution will stop after 1000 failed trials.
3. Run preprocess.
4. Substitute the variables, and do some smart adjustment:
   • Round all decimal variables to 5 significant figures.
   • Correct minus signs, e.g. x- -y become x+y.
   • Correct unit coefficient, e.g. x+1y become x+y.
5. Run postprocess.
6. Shuffle the answer options.
   If duplicated options are found, the whole execution will restart from step 1.

2. Reference

Common JavaScript Reference

structure	code
Declare variable	let myVariable = 1
If Then Else	if(condition){DoSomething}else{DoOtherThing}
Loop	for(let i=1; i<10; i++){DoSomething}
Array	arr = [1,2,3];
Array Element	x = arr[0]; y = arr[1];
Array Deconstruction	[a,b,c]=[1,2,3] (same as a=1; b=2; c=3;)
Array Spreading	sum(...[1,2,3]) (same as sum(1,2,3))
Print Debug	console.log(x)

Common LaTex Reference

symbol	code	LaTex
Superscript	a^{b}	$a^{b}$
Subscript	a_{b}	$a_{b}$
Fraction	\dfrac{a}{b}	$\dfrac{a}{b}$
Square Root	\sqrt{x}	$\sqrt{x}$
Equation Alignment	\begin{aligned} 2x-4&=10 \\ x&=7 \end{aligned}	$\begin{aligned} 2x-4&=10 \ x&=7 \end{aligned}$

Printing Variables

type	variable	print code	result
number	a = 1.23	*a	1.23
string	a = "hello"	*a	hello
boolean	a = true	*a	✓
boolean	a = false	*a	✕
point	a = [1,2]	*a	(1, 2)
combo	a = [true,true,false]	*a	I and II only
polynomial	a = poly	*a	1x^{3}+2x^{4}
trig value	a = ['sin',60]	*a	\sin 60°
trig value	a = ['sin','x']	*a	\sin x
trig expression	a = ['sin',90,-1,'x']	*a	\sin(90° - x)
surd	a = 18**0.5	*!a	3\sqrt{2}
surd	a = [2**0.5,3**0.5]	*!a	(\sqrt{2},\sqrt{3})
fraction	a = 0.5	*/a	\dfrac{1}{2}
small fraction	a = 0.5	*//a	1/2
bracket fraction	a = 0.5	*/(a)	\left ( \dfrac{1}{2} \right )
bracket fraction	a = 5	*/(a)	5
bracket fraction	a = -5	*/(a)	(-5)
sci notation	a = 0.0000123	**a	1.23 \times 10^{-5}
bracket negative	a = -2	*(a)	(-2)
bracket negative	a = 2	*(a)	2
absolute value	a = -1.23	`*	a
sign	a = 5	*^+_a	+
sign	a = -5	*^+_a	-
opposite sign	a = 5	*^-_a	-
opposite sign	a = -5	*^-_a	+
percentage	a = 0.123	*%a	12.3%
percentage	a = 0.123	*\%a	12.3%
ratio	a = 0.5	*:a	1:2
ratio	a = [2,4,6]	*:a	1:2:3
ineq sign	a = true	*^\gt_a	\gt
ineq sign	a = false	*^\gt_a	\lt
ineq sign	a > 0	*^\gt_a	\gt
ineq sign	a < 0	*^\gt_a	\lt
ineq sign	a = 0	*^\gt_a	=
ineq sign	(similar)	*^\lt_a	\lt
ineq sign	(similar)	*^\ge_a	\le
ineq sign	(similar)	*^\le_a	\ge
or trig root	a = [30,60,90,undefined]	`*	.a`
polar coordinates	a = [sqrt(3),3]	*.a	(2\sqrt{3}, 60°)
labeled value	a = [5,'x']	*=a	x = 5
labeled value	a = [5,'x','y']	*==a	y = 5
labeled value angle	a = [5,'x']	*=.a	x = 5°
labeled value angle	a = [5,'x','y']	*==.a	y = 5°

3. Advance Functions

Inline Code

• JavaScript code can be written in content using *{...} . For example, *{1+1} will print 2.
• *\{...\} do the same as *{...}, but also display the brackets in equation object.
• */{...} and **{...} work similarly.

Sections (Deprecated)

Sections can be used in content:

##1.1
section 1.1 here.
##
##1.2
section 1.2 here.
##

If sections = [[1,2]] is defined in populate, only section 1.2 will be shown.

Conditional Sections

We can decide whether to show a section or not by a condition: ##{condition}

##{true}
This will be shown.
##

##{false}
This will NOT be shown.
##

Options

With One Option

If the question contains only one answer option:

What is 1+1?

• *a

and populate contains

a = 2
options = {a: [3, 4, 5]}

then it's equivalent to

What is 1+1?

• 2
• 3
• 4
• 5

If the options is left blank: options = {a}, then RndShake() will be called on a to generate 3 random options.

With Two Options

If the question contains only two answer options:

What is 1+1?

• *a
• -*a

and populate contains

a = 2
options = {a: [3]}

then it's equivalent to

What is 1+1?

• 2
• -2
• 3
• -3

Answer

Normally, the first option must be the correct answer.
This can be changed by: answer = "B"
so that the second option is the correct answer.

Answer Option Mapping

To get the answer option key after shuffling, use {#A}. For example, if option A is shuffled to C, then {#A} will print C.