Some For Loop Exercises Loop Indices How many times will this program print "Hello World"?


for a=0:50
    disp('Hello World')
end

The code 0:50 creates a vector of integers starting at 0 and going to 50; this vector has 51 elements. "Hello World" will be printed once for each element in the vector (51 times). Loop Indices II How many times will this program print "Guten Tag Welt"?


for a=-1:-1:-50
    disp('Guten Tag Welt')
end

The code -1:-1:-50 creates a vector of integers starting at -1 and going backward to -50; this vector has 50 elements. "Guten Tag Welt" will be printed once for each element in the vector (50 times). Loop Indices III How many times will this program print "Bonjour Monde"?


for a=-1:1:-50
    disp('Bonjour Monde')
end

The code -1:1:-50 creates an empty vector with no elements. Since this is an empty vector the following error occurs: "Error in function range at line 1. You cannot specify a step size of zero for a range." Nested Loops How many times will this program print "Hola Mundo"?


for a=10:10:50
    for b=0:0.1:1
        disp('Hola Mundo')
    end
end

The outer loop (the loop with a) will be executed five times. Each time the outer loop is executed, the inner loop (the loop with b) will be executed eleven times, since 0:0.1:1 creates a vector with 11 elements. "Hola Mundo" will be printed 55 times. A tricky loop What sequence of numbers will the following for loop print?


n = 10;
for j = 1:n
    n = n-1;
    j
end

Explain why this code does what it does. In the first line, the value of n is set to 10. The code 1:n creates a vector of integers from 1 to 10. Each iteration through the loop sets j to the next element of this vector, so j will be sent to each value 1 through 10 in succession, and this sequence of values will be printed. Note that each time through the loop, the value of n is decreased by 1; the final value of n will be 0. Even though the value of n is changed in the loop, the number of iterations through the loop is not affected, because the vector of integers is computed once before the loop is executed and does not depend on subsequent values of n. Nested Loops II What value will the following program print?


count = 0;
for d = 1:7
   for h = 1:24
      for m = 1:60
         for s = 1:60
            count = count + 1;
         end
      end
   end
end
count

What is a simpler way to achieve the same results? The d loop will be executed seven times. In each iteration of the d loop, the h loop will be executed 24 times. In each iteration of the h loop, the m loop will be executed 60 times. In each iteration of the m loop, the s loop will be executed 60 times. So the variable count will be incremented 7 24 60 60 604800 times. A simpler way to achieve the same results is the command


7*24*60*60

Multiple Hypotenuses

Sides of a right triangle. Consider the right triangle shown in . Suppose you wish to find the length of the hypotenuse c of this triangle for several combinations of side lengths a and b ; the specific combinations of a and b are given in . Write a LABVIEW MATHSCRIPT's program to do this. Side Lengths a b 1 1 1 2 2 3 4 1 2 2

This solution was created by Heidi Zipperian:


a=[1 1 2 4 2]
b=[1 2 3 1 2]
for j=1:5
    c=sqrt(a(j)^2+b(j)^2)
end

A solution that does not use a for loop was also created by Heidi:


a=[1 1 2 4 2]
b=[1 2 3 1 2]
c=sqrt(a.^2+b.^2)