Conditionals

Conditional statements in R allow the control of flow in programs based on certain conditions. Using these statements different blocks of code can be executed depending on whether a condition is true or false.

If Statement

The if statement is used to execute a block of code if a condition is true. The general syntax is:

if (condition) {
  # Code to be executed if condition is true
}

If-Else Statement

The if-else statement allows the execution of a block of code if a condition is true, and another block of code if the condition is false. The general syntax is:

if (condition) {
  # Code to be executed if condition is true
} else {
  # Code to be executed if condition is false
}

Examples of if-else statements:

# If Statement
x <- 10

if (x > 5) {
  print("x is greater than 5")
}
# In this example, the code inside the if block will be executed because the condition x > 5 is true.


# If-Else Statement
x <- 3

if (x > 5) {
  print("x is greater than 5")
} else {
  print("x is less than or equal to 5")
}
# In this example, since the condition x > 5 is false, the code inside the else block will be executed.

Comparison Operators

Comparison operators in R allow the comparison of values and produce logical results. Here are some commonly used comparison operators:

• < (less than): Returns TRUE if the left operand is less than the right operand.
• > (greater than): Returns TRUE if the left operand is greater than the right operand.
• == (equal to): Returns TRUE if the left operand is equal to the right operand.
• != (not equal to): Returns TRUE if the left operand is not equal to the right operand.
• <= (less than or equal to): Returns TRUE if the left operand is less than or equal to the right operand.
• >= (greater than or equal to): Returns TRUE if the left operand is greater than or equal to the right operand.

Examples of comparison operators in R:

# Less than (<)
x <- 5
y <- 10

if (x < y) {
  print("x is less than y")
}
# Output: x is less than y


# Greater than (>)
x <- 5
y <- 10

if (x > y) {
  print("x is greater than y")
}
# No output in this case


# Equal to (==)
x <- 5
y <- 5

if (x == y) {
  print("x is equal to y")
}
# Output: x is equal to y


# Not equal to (!=)
x <- 5
y <- 10

if (x != y) {
  print("x is not equal to y")
}
# Output: x is not equal to y


# Less than or equal to (<=)
x <- 5
y <- 10

if (x <= y) {
  print("x is less than or equal to y")
}
# Output: x is less than or equal to y


# Greater than or equal to (>=)
x <- 5
y <- 5

if (x >= y) {
  print("x is greater than or equal to y")
}
# Output: x is greater than or equal to y

These operators are commonly used in conditional statements to compare values and make decisions.

Logical Operators

Logical operators in R can be used to combine or negate logical values. Here are the commonly used logical operators:

• && (and): Returns TRUE if both the left and right operands are TRUE.
• || (or): Returns TRUE if either the left or right operand is TRUE.
• ! (not): Negates a logical value. If the operand is TRUE, it returns FALSE, and if the operand is FALSE, it returns TRUE.

Examples of logical operators in R:

# AND (&&)
x <- 5
y <- 10

if (x > 0 && y > 0) {
  print("Both x and y are positive")
}
# Output: Both x and y are positive


# OR (||)
x <- 5
y <- -10

if (x > 0 || y > 0) {
  print("Either x or y is positive")
}
# Output: Either x or y is positive


# NOT (!)
x <- 5

if (!(x == 10)) {
  print("x is not equal to 10")
}
# Output: x is not equal to 10

Logical operators are often used to combine multiple conditions in conditional statements or to negate a condition.

These are the basic conditional statements, comparison operators, and logical operators in R. They can be leveraged to control the flow of a program, compare values, and make decisions based on specific conditions.