UM0715

Expression

Doc ID 15798 Rev 2

17/24

5

Expression

5.1

Expressions

5.1.1

Precedence

The + and - operators have lower precedence than *, / and MOD (modulus), which have

equal precedence and are evaluated left to right. ! (factorial) has the highest precedence.

Example:

(x + y) * 2

add x to y and multiply by two.

5.2

String expressions

All strings are stored internally in ASCII format, as NUL terminated arrays. Use of extremely

large strings is likely to slow down the program, since most operations involve internal

copying of strings.

A string literal consists of one or more concatenated quotes. A string can be spread over

several lines, but the newline character is not allowed inside quotes. To enclose a quotation

mark in astring, use double quotes.

10 LET A$ = ?And God said ??Let there be light?? ?

?and there was light.? ?And God saw the light, that it was good.?

is an example of a legal string. Note that the start of the second line contains white space at

the beginning to tell the interpreter it is a continuation of the previous line.

Table 2.

Expression

Expression

Symbol

+Sum.

-

Subtraction.

*

Multiplication.

/

Division.

MOD

MOD calculates the modulus of a number. Both sides of the expression

should be of the same sign. x MOD 0 is an error. Division by zero is

also an error.

!

Factorial.

POW(x,y)

POW( x + y, 2)

raise x + y to the power 2.

INT(X)

Force an expression to be the nearest exact integer.

LEN($A)

Return the length of the string A.