Assignment Operations: Difference between revisions

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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:


  00010 let x = 5
  00010 let x = 5 ! correct


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


  00010 let 5 = x
  00010 let 5 = x ! incorrect


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.

Revision as of 10:01, 9 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.