In programming, you will often come across situations where you will need to evaluate multiple conditions. For example, you may want to perform an action when the price of a stock is above 10 but below 12. Logical operators come into play in such situations. These logical operators allow a program to make a decision based on multiple conditions.

In R, there are five logical operators.

AND (&)

This is called the Logical AND Operator. The logical AND operator (&) returns the boolean value true if both operands are true and returns false otherwise. The following examples illustrate this:

#Assign values to Stock A and Stock B
stock_A = 10
stock_B = 12
#Test if Stock A is equal to 10 and Stock B is equal to 12.
(stock_A==10) & (stock_B==12)

This will return TRUE if both the conditions evaluate to TRUE. The result will be TRUE as shown below:

> (stock_A==10) & (stock_B==12)
[1] TRUE

Below is another example of & operator on two vectors.

# The following are two vectors containing returns from two stocks over the past five days.
stock_A <- c(10, 8, 9, 11, 12)
stock_B <- c(8,11,10,10,12)
# Stock A exceeds 10 (Inclusive) and Stock B is below 10 (Inclusive)
(stock_A >=10) & (stock_B <=10)