What is the syntax to perform if else with multiple conditions in R? In R Programming, you can perform if else with multiple conditions by using the if…else statement or the ifelse() function. And, you would need to use logical operators & for AND, | for OR.

1. Quick Examples of if else Multiple Conditions

The following are quick examples of performing if else with multiple conditions.

``````
# multiple conditions with & (AND)
a = 50
if( a >= 40 & b <= 60 ){
print('a value is in between 40 and 60')
}

# Multiple conditions with | (OR)
str = 'HELLO'
if(str == "HELLO" | str == "hello"){
print("str value is hello")
}

# Using ifelse() statement
a = 50
val = ifelse(a >= 40 & b <= 60, 'TRUE', "FALSE")
print(val)

# Using multiple conditions on DataFrame
df\$size <- ifelse(df\$chapters > 0 & df\$chapters < 20, 'SMALL','BIG')
``````

2. R if else Multiple Conditions with And (&)

R uses `&` as logical AND that would be used to check if else statement with multiple conditions.

The logical AND (`&`) operator will be `TRUE` if and only if all the operands are `TRUE`. Otherwise, it will be `FALSE`. It evaluates operads from left to right and returns immediately when the first condition or operand becomes `FALSE`.

``````
# Multiple conditions with and
a = 50
if( a >= 40 & a <= 60 ){
print('a value is in between 40 and 60')
}

# Output
# [1] "a value is in between 40 and 60"
``````

3. R if else Multiple Conditions with or(|)

R uses `|` as local OR that would be used to check if else statements with multiple conditions.

The logical OR (`|`) operator will be `TRUE` if any operands are `TRUE`. If all operands `FALSE`, it will be `FALSE`. It evaluates operads from left to right and returns immediately when the first condition or operand becomes `TRUE`.

``````
# Multiple conditions with or
str = 'HELLO'
if(str == "HELLO" | str == "hello"){
print("str value is hello")
}

# Output
# [1] "str value is hello"
``````

4. Using ifelse() Function

R Base also has a function `ifelse()` that can be used similarly to the if…else statement. This function takes three parameters. The first one represents the condition of single/multiple, the second one represents the value to be returned when the condition evaluates `TRUE`, and the third one represents the value to be returned when the condition evaluates `FALSE`.

``````
# Using ifelse() statement
a=50
val = ifelse(a >= 40 & a <= 60, 'TRUE', "FALSE")
print(val)

# Output
#[1] "TRUE"
``````

5. Multiple Conditions with DataFrame

The following example shows that how to add a new column `size` to the DataFrame by using if else with multiple conditions in R. Here, we use dollar (\$) in R to refer to DataFrame columns.

``````
# Create dataframe
df=data.frame(id=c(11,22,33,44,55),
pages=c(32,45,33,22,56),
name=c("spark","python","R","java","jsp"),
chapters=c(76,86,11,15,7),
price=c(144,553,321,567,890))

# Display the dataframe
print(df)

# Using multiple conditions
df\$size <- ifelse(df\$chapters > 0 & df\$chapters < 20, 'SMALL','BIG')
``````

Yields below output.

Conclusion

To perform multiple conditions in R you should use logical operators within if…else statement or the iflese() functions. The logical operators are & for AND, and | for OR. The logical AND (`&`) operator will be `TRUE` if and only if all the operands are `TRUE`. Otherwise, it will be `FALSE`. It evaluates operads from left to right and returns immediately when the first condition or operand becomes `FALSE`. The logical OR (`|`) operator will be `TRUE` if any operands are `TRUE`. if all operands `FALSE`, it will be `FALSE`. It evaluates operads from left to right and returns immediately when the first condition or operand becomes `TRUE`.