x=10
 if(x==1)
 {
   print(x)
 }else if(x==10)
 {
   print("ten")
 }else
 {
   print("nothing")
 }
#[1] "ten"

 
 ifelse(x<5,"yes","no")
#[1] "no"
 ifelse(x<5,0,1)
#[1] 1
 

# One interesting issue with R when dealing with "else" statement.
# Let's try two code snippets to understand this issue

# code 1
x=10
if(x==10)
{
  print(x)
}else
{
  print('wrong')
}
# Output
#  x=10
# > if(x==10)
# + {
# +   print(x)
# + }
# [1] 10
# > else
# Error: unexpected 'else' in "else"
# > {
# +   print('wrong')
# + }
# [1] "wrong"

# Code 2

 x=10
 if(x==10)
 {
   print(x)
 }else
 {
   print('wrong')
 }
#[1] 10

# As you can see that in code 1, the else statement starts after }, in this case, R don't know if you have else block or not, hence, an error.