1. Conditional syntax

if(TRUE){
  print('if true')
}else if(FALSE){
  print('else if true')
}else{
  print('neither true')
}

## [1] "if true"

if(FALSE){
  print('if true')
}else if(TRUE){
  print('else if true')
}else{
  print('neither true')
}

## [1] "else if true"

if(FALSE){
  print('if true')
}else if(FALSE){
  print('else if 2 true')
}else if(FALSE){
  print('else if 2 true')
}else if(TRUE){
  print('else if 3 true')
}else{
  print('neither true')
}

## [1] "else if 3 true"

x = 6
if(x == 0){
  print('zeo true')
}else if(x == 1){
  print('one 1 true')
}else if(x == 2){
  print('one 2 true')
}else if(x == 3){
  print('one 3 true')
}else if(x == 4){
  print('one 4 true')
}else if(x == 5){
  print('one 5 true')
}else{
  print('neither true')
}

## [1] "neither true"