Programming in LabVIEW MathScript

Some If Statement Exercises

EXERCISE 1

What will the following LABVIEW MATHSCRIPT code print?

a = 10;
if a ~= 0
    disp('a is not equal to 0')
end

[ SHOW SOLUTION ]

EXERCISE 2

What will the following LABVIEW MATHSCRIPT code print?

a = 10;
if a > 0
    disp('a is positive')
else
    disp('a is not positive')
end

[ SHOW SOLUTION ]

EXERCISE 3

What will the following LABVIEW MATHSCRIPT code print?

a = 5;
b = 3;
c = 2;
if a < b*c
    disp('Hello world')
else
    disp('Goodbye world')
end

[ SHOW SOLUTION ]

EXERCISE 4

Suppose the code in Exercise 2 is modified by adding parentheses around a > 0. What will it print?

a = 10;
if (a > 0)
    disp('a is positive')
else
    disp('a is not positive')
end

[ SHOW SOLUTION ]

EXERCISE 5

Suppose the code in Exercise 3 is modified by adding the parentheses shown below. What will it print?

a = 5;
b = 3;
c = 2;
if (a < b)*c
    disp('Hello world')
else
    disp('Goodbye world')
end

[ SHOW SOLUTION ]

EXERCISE 6

What will the following LABVIEW MATHSCRIPT code print?

p1 = 3.14;
p2 = 3.14159;
if p1 == p2
    disp('p1 and p2 are equal')
else
    disp('p1 and p2 are not equal')
end

[ SHOW SOLUTION ]

EXERCISE 7

What will the following LABVIEW MATHSCRIPT code print?

a = 5;
b = 10;
if a = b
    disp('a and b are equal')
else
    disp('a and b are not equal')
end

[ SHOW SOLUTION ]

EXERCISE 8

For what values of the variable a will the following LABVIEW MATHSCRIPT code print 'Hello world'?

if ~ a == 0
    disp('Hello world')
else
    disp('Goodbye world')
end

[ SHOW SOLUTION ]

EXERCISE 9

For what values of the variable a will the following LABVIEW MATHSCRIPT code print 'Hello world'?

if a >= 0 && a < 7
    disp('Hello world')
else
    disp('Goodbye world')
end

[ SHOW SOLUTION ]

EXERCISE 10

For what values of the variable a will the following LABVIEW MATHSCRIPT code print 'Hello world'?

if a < 3 || a > 10
    disp('Hello world')
else
    disp('Goodbye world')
end

[ SHOW SOLUTION ]

EXERCISE 11

For what values of the variable a will the following LABVIEW MATHSCRIPT code print 'Hello world'?

if a < 7 || a >= 3
    disp('Hello world')
else
    disp('Goodbye world')
end

[ SHOW SOLUTION ]

EXERCISE 12

Write an if statement that will print 'a is very close to zero' if the value of the variable a is between -0.01 and 0.01.

The While Loop

The while loop is similar to the for loop in that it allows the repeated execution of LABVIEW MATHSCRIPT statements. Unlike the for loop, the number of times that the LABVIEW MATHSCRIPT statements in the body of the loop are executed can depend on variable values that are computed in the loop. The syntax of the while loop has the following form:

while expression
    % LABVIEW MATHSCRIPT command 1
    % LABVIEW MATHSCRIPT command 2
    % More commands to execute repeatedly until expression is not 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, consider the following while loop:

n = 1
while n < 3
    n = n+1
end

This code creates the following output:

n =

     1

n =

     2

n =

     3

Note that in all of this example, the LABVIEW MATHSCRIPT commands inside the while loop are indented relative to the while and end statements. This is not required by LABVIEW MATHSCRIPT but is common practice and makes the code much more readable.