SIMSCRIPT II.5 Programming Language

SIMSCRIPT II.5 Basic Concepts
An expression is written as a string of variable names, constants, arithmetic operators, and parentheses.
Any number of spaces from zero upward may be used to separate the parts of an expression.
Therefore, A+B, A+ B, A + B and A +B are treated identically. The exponentiation operator,
**, is treated as a single unit and no spaces may appear between its two asterisks. Some example
expressions are given in table 1-2.
Table 1-2. Sample Mathematical Expressions
_______________________________________________________________________________
Expression
PRICE
Comment
A variable is itself an expression
53 A constant is also an expression
(PRICE)
Parentheses are optional
DUEIN - DUEOUT
PRICE * QUANTITY
PRICE * (ORDER - SALES)
Parentheses change precedence order
A + B + C + D
X ** 2 In mathematical notation, this is X 2
A + X ** 2 + X ** 4
Equivalent to the following:
A + (X ** 2) + (X ** 4)
X + Y / Z
This means
X + (Y/Z),
not:
(X + Y)/Z
- A ** B This means -(A B ), not (-A) B
_______________________________________________________________________________
1.6 Computing Variable Values
One way of assigning a value to a program variable is to use a read statement. Another way is to
use a let statement. The general form of this statement is:
let variable = expression
as in the statements:
let X = 0
let X = (Y + 1)/15
let PRICE = QUANTITY * SALES.PRICE
let BALANCE = STOCK - PURCHASE
let UNIT.COST = TOTAL.COST / NUMBER.OF.UNITS
let AREA = 3.14 * RADIUS ** 2
5