As part of Data Science tutorial Series in my previous post I posted on basic data types in R. I have kept the tutorial very simple so that beginners of R programming may takeoff immediately.
Please find the online R editor at the end of the post so that you can execute the code on the page itself.
In this section we learn about control structures loops used in R. Control strcutures in R contains conditionals, loop statements like any other programming languages.
Loops are very important and forms backbone to any programming languages.Before we get into the control structures in R, just type as below in Rstudio:
?control
If else statement:
#See the code syntax below for if else statement
if(x>1){
print("x is greater than 1")
}else{
print("x is less than 1")
}#See the code below for nested if else statement
x=10
x=10
if(x>1 & xprint("x is between 1 and 7")}else if(x>8 & xprint("x is between 8 and 15")
}[1] "x is between 8 and 15"
For loops:
As we know for loops are used for iterating items
#Below code shows for loop implementation
x = c(1,2,3,4,5)
for(i in 1:5){
print(x[i])
}
[1] 1
[1] 2
[1] 3
[1] 4
[1] 5
While loop :
#Below code shows while loop in R
x = 2.987
while(x x = x + 0.987
print(c(x,x-2,x-1))
}
[1] 3.974 1.974 2.974
[1] 4.961 2.961 3.961
[1] 5.948 3.948 4.948
Repeat Loop:
The repeat loop is an infinite loop and used in association with a break statement.
#Below code shows repeat loop:
a = 1
repeat { print(a) a = a+1 if(a > 4) break }
[1] 1
[1] 2
[1] 3
[1] 4
Break statement:
A break statement is used in a loop to stop the iterations and flow the control outside of the loop.
#Below code shows break statement:
x = 1:10
for (i in x){
if (i == 2){
break
}
print(i)
}
[1] 1
Next statement:
Next statement enables to skip the current iteration of …read more
Source:: r-bloggers.com