How to convert a string to an expression in R Programming

parse() function in R Language is used to convert an object of character class to an object of expression class.

Syntax: parse(text = character)

Parameters:
character: Object of character class

Example 1:

# R program to convert
# character to expression

# Creating an object of character class
x <- "sin(pi / 2)"

# Class of object
class(x)

# Calling parse() Function
x1 <- parse(text = x)

# Class of parsed object
class(x1)

Output:

[1] "character"
[1] "expression"

Example 2:

# R program to convert
# character to expression

# Creating an object of character class
x <- "2 ^ 3"

# Evaluating the value of object
eval(x)

# Calling parse() Function
x1 <- parse(text = x)

# Evaluating the value of object
eval(x1)

Output:

[1] "2^3"
[1] 8

 

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