Loops (R Loops) are used to repeat the execution of a block of statements based on some predefined conditions. In R Programming we have the following types of loops that can be used as per development requirements.

Repeat Loop in R Programming

Repeat loop in R executes the set of statements until the defined condition is satisfied

1. #Print some value using Repeat Loop
2. count <- 1
4. repeat {
5. print("R Programming")
6. count <- count+1
8. if(count > 5) {
9. break
10. }
11. }

and output is

1. [1] "R Programming"
2. [1] "R Programming"
3. [1] "R Programming"
4. [1] "R Programming"
5. [1] "R Programming"

Another Example

1. #Print table of 10 using Repeat Loop
2. a <- 10
3. count <- 1
5. repeat {
6. print(a*count)
7. count <- count+1
9. if(count > 10) {
10. break
11. }
12. }

and output is

1. [1] 10
2. [1] 20
3. [1] 30
4. [1] 40
5. [1] 50
6. [1] 60
7. [1] 70
8. [1] 80
9. [1] 90
10. [1] 100

While Loop in R Programming

While loop checks the condition before starting loop execution and executes the set of statements while the defined condition is true.

1. #Declare and Initialise a varable
2. a <- 1
4. #Check condition in a while loop
5. while(a<=5){
6. print(a)
7. a <- a+1
8. }

and output is

1. [1] 1
2. [1] 2
3. [1] 3
4. [1] 4
5. [1] 5

FOR Loop in R Programming

When you need to execute a code a specific number of times then FOR loop comes into action. Here we'll see how to iterate a vector using FOR loop.

1. #Declare and Initialise a Vector
2. a <- c(10,TRUE,"Ashish",2.4)
4. #Iterate vector using FOR loop
5. for(i in a){
6. print(i)
7. }

and output is

1. [1] "10"
2. [1] "TRUE"
3. [1] "Ashish"
4. [1] "2.4"

Cheers 🙂 Happy Learning

PL/SQL While Loop

PL/SQL WHILE loop is used to execute statements as long as given condition is true and the condition is checked at the beginning of each iteration

The syntax of PL/SQL While loop is like this

WHILE condition

statements to execute

END LOOP;

PL/SQL Loops , Iterative Statement in PL/SQL

Loops are used to repeat execution of a statement or a set of statements multiple times on base of a condition or expression
EXIT and EXIT-WHEN keywords are used to terminate the loop

EXIT- terminates the loop unconditionally and passes control to the next statement after the loop
EXIT-WHEN- terminates the loop when EXIT-WHEN clause is checked and if returns true then the loop is terminated and control is passed to next statement after the loop

The basic syntax of Loop in PL/SQL is like this

LOOP

Set of statements

END LOOP;