# Conditional Statements Exercises - Solutions¶

For these exercises, use what you have learned about if,else if, and else statements to answer the questions! The first exercise is done for you as an example:

Example: Write a script that prints "Hello" if the variable x is equal to 1:

In [1]:

    x <- 1

    if (x ==1){
        print("Hello")
    }

    [1] "Hello"

### Exercise Problems¶

Ex 1: Write a script that will print "Even Number" if the variable x is an even number, otherwise print "Not Even":

In [5]:

    x <- 3 # Change x to test

    if (x%%2 == 0){
        print('Even Number')
    }else{
        print('Not Even')
    }

    [1] "Not Even"

Ex 2: Write a script that will print 'Is a Matrix' if the variable x is a matrix, otherwise print "Not a Matrix". Hint: You may want to check out help(is.matrix)

In [6]:

    x <- matrix()

    if (is.matrix(x)){
        print('Is a Matrix')
    }else{
        print("Not a Matrix")
    }

    [1] "Is a Matrix"

Ex 3: Create a script that given a numeric vector x with a length 3, will print out the elements in order from high to low. You must use if,else if, and else statements for your logic. (This code will be relatively long)

In [10]:

    x <- c(3,7,1)

    if (x[1] > x[2]){
        fir <- x[1]
        sec <- x[2]
    } else {
        fir <- x[2]
        sec <- x[1]
    }
    if ( x[3] > fir & x[3] > sec ) {
        thi <- sec
        sec <- fir
        fir <- x[3]
    } else if ( x[3] < fir & x[3] < sec ) {
        thi <- x[3]
    } else {
        thi <- sec
        sec <- x[3]
    }

    print(paste(fir, sec, thi))

    [1] "7 3 1"

Ex 4: Write a script that uses if,else if, and else statements to print the max element in a numeric vector with 3 elements.

In [12]:

    x <- c(20, 10, 1)

    if (x[1] > x[2] & x[1] > x[3] ) {
        print(x[1] )
    } else if (x[2] > x[3] ) {
        print(x[2])
    } else {
        print(x[3])
    }

    [1] 20

## Great Job!¶