Assignment Operations: Difference between revisions

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[[Numeric]] and [[String]] [[Variable|variables]] both may be used with regular and forced assignment operators.
[[Numeric]] and [[String]] [[Variable|variables]] both may be used with regular and forced assignment operators.


==Regular Assignment==
===Regular Assignment===


The equal sign '''=''' simply makes the variable on the left side of it equal to the value on the right side of it. The example below assigns the value of 5 to the variable x:
The equal sign '''=''' simply makes the variable on the left side of it equal to the value on the right side of it. The example below assigns the value of 5 to the variable x:
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The disadvantage of the equal sign assignment operator '''=''' is that it may only be used as a separate statement.
The disadvantage of the equal sign assignment operator '''=''' is that it may only be used as a separate statement.


==Forced Assignment==
===Forced Assignment===


If your programming needs call for multiple operations in one statement, you may use the '''forced assignment''' operator ''':='''. The example below assigns the value of 5 to x and then compares the value of x (which is now 5) to the value of 2:
If your programming needs call for multiple operations in one statement, you may use the '''forced assignment''' operator ''':='''. The example below assigns the value of 5 to x and then compares the value of x (which is now 5) to the value of 2:

Revision as of 17:09, 10 January 2012

There are two assignment operators in BR: the equal sign =, which denotes regular assignment, and the colon-equal sign :=, which denotes forced assignment,

They are similar in how they work with a slight difference.

Both of them are Binary operators, which means they take two arguments - one on the left, and another one on the right.

Numeric and String variables both may be used with regular and forced assignment operators.

Regular Assignment

The equal sign = simply makes the variable on the left side of it equal to the value on the right side of it. The example below assigns the value of 5 to the variable x:

00010 let x = 5 ! correct

Note that you cannot do the reverse. The example below will result in an error.

00010 let 5 = x ! incorrect

The disadvantage of the equal sign assignment operator = is that it may only be used as a separate statement.

Forced Assignment

If your programming needs call for multiple operations in one statement, you may use the forced assignment operator :=. The example below assigns the value of 5 to x and then compares the value of x (which is now 5) to the value of 2:

00010 if (x:=5) > 2 then print "The forced-assigned value is larger than 2"

Note that when this assignment operator is used in any expression (for example: in the condition of an IF THEN statement), parentheses must be used to clarify the order of execution Otherwise, unexpected results may occur.