`ts
data : number[] // the actual array

length : number // length of this.data

max: number (read-only) // highest number in the array.

min: number (read-only) // lowest number in the array.

difference: number (read-only) // difference between max and min.

sum: number (read-only)

average: number (read-only)

product: number (read-only)

median: number (read-only)

areOrdered: boolean (read-only) // true if numbers are in ascending order.

isEmpty : boolean (read-only)

notEmpty : boolean (read-only)

copy : this (read-only)
// a copy of the instance, containing an independent copy of this.data
// that can be manipulated separately.

className : string (read-only)
`


`ts
allInRange(range: [min, max]): boolean
// Example: this.data = [10,13,20,22,25]
// this.allInRange([13, 20]); // --> false
// this.allInRange([10, 25]); // --> true

order(): void
// puts numbers in this.data in ascending order.

shuffle(): void
// randomizes the order of numbers in this.data .

set(newArray): void
// Changes value of this.data to newArray without breaking its memory reference.
// So if there are copies of this.data, the copies will be updated as well.

append(values): this
// attaches values to end of this.data.

prepend(values): this
// attaches values to beginning of this.data.

moveByIndex(currentIndex, newIndex): this
// moves an item, identified by currentIndex, to newIndex.
// Both currentIndex and newIndex can be negative or positive.

forEach(iterationFunction): void
// Behaves same as Array.forEach()
// iterationFunction = function(currentValue, currentIndex?, entireArray?): any

asString(glue? = ', '): string
// Does same thing as Array.join()
`
NOTICE: For all the methods below, any parameter called value cannot be an object,
and any parameter called values cannot contain an object.
This does not include arrays. Arrays are OK, as long as they don't contain objects.
`ts
has(value): boolean
// returns true if this.data contains value.

hasAll(values): boolean
// returns true if this.data contains every value in values.

hasAny(values): boolean
// returns true if this.data contains at least 1 value in values.

hasAdjacent(values): boolean
// returns true if this.data contains exact sequence of values.
// Example: if this.data is [10,1,2,3,11], then this.hasAdjacent([1,2,3])
// returns true.

startsWith(values): boolean
// returns true if this.data starts with exact sequence of values.
// always returns false if values contains object.

endsWith(values): boolean
// returns true if this.data ends with exact sequence of values.
// always returns false if values contains object.

matches(values): boolean
// returns true if this.data matches values exactly.

firstIndexOf(value): number
// returns index of first instance of value found in this.data

lastIndexOf(value): number
// returns index of last instance of value found in this.data

indexesOf(value): number[]
// returns indexes of every instance of value found in this.data
`

For the next 3 methods:
testFunction is a callback with same signature as callback passed to
Array.filter() :
testFunction(item, index?, theArray?): boolean
If item passes a test, testFunction returns true.
`ts
allPass(testFunction): boolean
// returns true if all items pass test.

anyPass(testFunction): boolean
// returns true if at least 1 item passes.

indexesThatPass(testFunction): number[]
// returns indexes of items that pass test.
`
The methods below are not important to know about in order to use this
class. They're inherited from BaseClass .
`ts
protected _createGetterAndOrSetterForEach(
propertyNames: string[],
configuration: IGetterSetterConfiguration
) : void
/*
Use this method when you have a bunch of properties that need getter and/or
setter functions that all do the same thing. You pass in an array of string
names of those properties, and the method attaches the same getter and/or
setter function to each property.
IGetterSetterConfiguration is this object:
{
get_setterFunction?: (
propertyName: string, index?: number, propertyNames?: string[]
) => Function,
// get_setterFunction takes the property name as first argument and
// returns the setter function. The setter function must take one
// parameter and return void.

get_getterFunction?: (
propertyName: string, index?: number, propertyNames?: string[]
) => Function
// get_getterFunction takes the property name as first argument and
// returns the getter function. The getter function must return something.
}
*/


protected _returnThis_after(voidExpression: any) : this
// voidExpression is executed, then function returns this.
// Even if voidExpression returns something, the returned data isn't used.

protected _errorIfPropertyHasNoValue(
property: string, // can contain dot-notation, i.e., 'property.subproperty'
propertyNameInError? = ''
) : void
// If value of this[property] is undefined or null, it triggers fatal error:
// The property "${propertyNameInError}" has no value.
`