Find All Names in an Expression

Description

Return a character vector containing all the names which occur in an expression or call.

Usage

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all.names(expr, functions = TRUE, max.names = -1L, unique = FALSE)

all.vars(expr, functions = FALSE, max.names = -1L, unique = TRUE)

Arguments

expr

an expression or call from which the names are to be extracted.

functions

a logical value indicating whether function names should be included in the result.

max.names

the maximum number of names to be returned. -1 indicates no limit (other than vector size limits).

unique

a logical value which indicates whether duplicate names should be removed from the value.

Details

These functions differ only in the default values for their arguments.

Value

A character vector with the extracted names.

See Also

substitute to replace symbols with values in an expression.

Examples

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all.names(expression(sin(x+y)))
all.names(quote(sin(x+y))) # or a call
all.vars(expression(sin(x+y)))

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