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do

do expression [as scriptLanguage]

The do keyword forces HyperCard to evaluate expression and to send the result as a message to the current card.

The value of expression can contain more than one line. For example, if you have a series of statements in a card field called Example, HyperCard will apply do to each line:

do card field "Example"

When you use the as scriptLanguage form, HyperCard executes the script in expression using the OSA-compliant scripting component named in scriptLanguage:

do field 1 as AppleScript

do theScript as UserTalk

You can also send do from the Message box.

Demo Script

on doLast3Lines

  put the number of lines of bkgnd field "Demo Script" into N

  do line (N - 2) to N of bkgnd field "Demo Script"

end doLast3Lines

put sqrt(2)

beep

flash

Placeholders

expression

HyperTalk Definition

Any HyperTalk expression. All expressions evaluate to text, a number, or a constant.

For example:

true

sin(90)

"this is" && it

(3+2) = 5

the heapspace div 1024

Note: Formally, HyperCard distinguishes between factors (simple values) and expressions. The difference between factors and expressions matters only if you like to drop parentheses. Most functions take factors as their parameters, which is why length of 3 + 5 returns 6 and length of (3 + 5) returns 1. In short, always use parentheses to group things the way you want them to evaluate, and you won’t have to worry about the difference between factors and expressions.

AppleScript Definition

Any series of words that has a value.

if (multiple-statement)

if (single-statement)