What are the restrictions on creating a vector in R?

There are four main restrictions on creating a vector in R. We must remember these restrictions while creating any type of vector −

• A vector name cannot have % sign.

• A vector name cannot start with a number.

• A vector can start with a dot but it should not have a number after it.

• A vector cannot start with underscore.

Examples

Vectors with % sign −

x1%<-1:20
Error: unexpected input in "x1%<-1:20"
x1%first<-1:20
Error: unexpected input in "x1%first<-1:20"
%x1<-1:20
Error: unexpected input in "%x1<-1:20"
x1_%_first<-1:20
Error: unexpected input in "x1_%_first<-1:20"
x1first_1_%<-1:20
Error: unexpected input in "x1first_1_%<-1:20"
x1first__%<-1:20
Error: unexpected input in "x1first__%<-1:20"

Vectors starting with a number −

1x<-1:20
Error: unexpected symbol in "1x"
1_x<-1:20
Error: unexpected input in "1_"
101_x<-1:20
Error: unexpected input in "101_"
123_x<-1:20
Error: unexpected input in "123_"
1number_x<-1:20
Error: unexpected symbol in "1number_x"
1number<-1:20
Error: unexpected symbol in "1number"

Vectors starting with a dot −

.x1<-1:10
.x1
[1] 1 2 3 4 5 6 7 8 9 10
.1x<-1:10
Error: unexpected symbol in ".1x"
.1_x<-1:10
Error: unexpected input in ".1_"
.100_x<-1:10
Error: unexpected input in ".100_"
.1of_x<-1:10
Error: unexpected symbol in ".1of_x"
.2of_x<-1:10
Error: unexpected symbol in ".2of_x"
.1ofx<-1:10
Error: unexpected symbol in ".1ofx"

Vectors starting with underscore −

_x1<-1:10
Error: unexpected input in "_"
_first<-1:10
Error: unexpected input in "_"
_first_variable<-1:10
Error: unexpected input in "_"
_variable1<-1:10
Error: unexpected input in "_"
_firstvariable<-1:10
Error: unexpected input in "_"
_V1<-1:10
Error: unexpected input in "_"
_1_var <-1:10
Error: unexpected input in "_"