The If Statement The if statement is one way to make the sequence of computations executed by LABVIEW MATHSCRIPT depend on variable values. The if statement has several different forms. The simplest form is


if expression
    % LABVIEW MATHSCRIPT commands to execute if expression is true
end

where expression is a logical expression that is either true or false. (Information about logical expressions is available in Programming in LABVIEW MATHSCRIPT-Logical Expressions.) For example, the following if statement will print "v is negative" if the variable v is in fact negative:


if v < 0
    disp('v is negative')
end

A more complicated form of the if statement is


if expression
    % LABVIEW MATHSCRIPT commands to execute if expression is true
else
    % LABVIEW MATHSCRIPT commands to execute if expression is false
end

For example, the following if statement will print "v is negative" if the variable v is negative and "v is not negative" if v is not negative:


if v < 0
    disp('v is negative')
else
    disp('v is not negative')
end

The most general form of the if statement is


if expression1
    % LABVIEW MATHSCRIPT commands to execute if expression1 is true
elseif expression2
    % LABVIEW MATHSCRIPT commands to execute if expression2 is true
elseif expression3
    % LABVIEW MATHSCRIPT commands to execute if expression3 is true
    ...
else
    % LABVIEW MATHSCRIPT commands to execute if all expressions are false
end

The following if statement is an example of this most general statement:


if v < 0
    disp('v is negative')
elseif v > 0
    disp('v is positive')
else
    disp('v is zero')
end

Note that in all of the examples in this module, the LABVIEW MATHSCRIPT commands inside the if statement are indented relative to the if, else, elseif, and end statements. This is not required by LABVIEW MATHSCRIPT but is common practice and makes the code much more readable.