Putproperty Command Example

Details

Action

Putproperty Prop in Proptype of target

or

Putproperty Prop Proptype target

has the effect of placing in the 'proptype' property of target the item Prop. The 'proptype' property is overwritten. Target is the name of an object, and is not evaluated.

make variable degree;

make f(x) x^2;

putproperty 2 in degree of f;

Getproperty(f,degree)

returns 2

Whenever a property is assigned to a name, the property also has a name. We call that the Propname. The property itself is some object, such as a variable, or a list, and is designated the Prop.

Suppose we want to define a 'family tree' as a miniature database.

We have certain family members. Say William and Sarah are the parents of

John. John is married to Mary and they have children Liza and Tom.

Suppose William is 56 and Sarah is 50 years of age. John is 33 and

Mary is 34. Liza and Tom are twins and they are both 8 years old.

In MathScript, each of these names must be declared first as variables:

Make variable william

Make variable sarah

Make variable john

Make variable mary

Make variable liza

Make variable tom

And we have propnames: Father, Mother, Husband, Wife, Age, Children

Make variable father

Make variable mother

Make variable husband

Make variable wife

Make variable children

Make variable age

Now, we begin to create this database by entering:

putproperty william in father of john;

This creates for John a 'father' property. And it inserts William as the value of the father property of John.

To check this, we use the dual function getproperty.

Getprop(john,father) returns as its value: William.

Now enter

putproperty sarah in mother of john;

putproperty mary in wife of john;

putproperty 33 in age of john;

putproperty list(liza,tom) in children of john;