R: Assign a Value to a Name

assign {base} | R Documentation

## Assign a Value to a Name

### Description

Assign a value to a name in an environment.

### Usage

    assign(x, value, pos = -1, envir = as.environment(pos),
           inherits = FALSE, immediate = TRUE)

### Arguments

`x` | a variable name, given as a character string. No coercion is done, and the first element of a character vector of length greater than one will be used, with a warning.
`value` | a value to be assigned to `x`.
`pos` | where to do the assignment. By default, assigns into the current environment. See ‘Details’ for other possibilities.
`envir` | the `environment` to use. See ‘Details’.
`inherits` | should the enclosing frames of the environment be inspected?
`immediate` | an ignored compatibility feature.

### Details

There are no restrictions on the name given as `x`: it can be a non-syntactic name (see `make.names`).

The `pos` argument can specify the environment in which to assign the object in any of several ways: as `-1` (the default), as a positive integer (the position in the `search` list); as the character string name of an element in the search list; or as an `environment` (including using `sys.frame` to access the currently active function calls). The `envir` argument is an alternative way to specify an environment, but is primarily for back compatibility.

`assign` does not dispatch assignment methods, so it cannot be used to set elements of vectors, names, attributes, etc.

Note that assignment to an attached list or data frame changes the attached copy and not the original object: see `attach` and `with`.

### Value

This function is invoked for its side effect, which is assigning `value` to the variable `x`. If no `envir` is specified, then the assignment takes place in the currently active environment.

If `inherits` is `TRUE`, enclosing environments of the supplied environment are searched until the variable `x` is encountered. The value is then assigned in the environment in which the variable is encountered (provided that the binding is not locked: see `lockBinding`: if it is, an error is signaled). If the symbol is not encountered then assignment takes place in the user's workspace (the global environment).

If `inherits` is `FALSE`, assignment takes place in the initial frame of `envir`, unless an existing binding is locked or there is no existing binding and the environment is locked (when an error is signaled).

### References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.

### See Also

`<-`, `get`, `exists`, `environment`.

### Examples

    for(i in 1:6) { #-- Create objects  'r.1', 'r.2', ... 'r.6' --
        nam <- paste("r", i, sep = ".")
        assign(nam, 1:i)
    }
    ls(pattern = "^r..$")

    ##-- Global assignment within a function:
    myf <- function(x) {
        innerf <- function(x) assign("Global.res", x^2, envir = .GlobalEnv)
        innerf(x+1)
    }
    myf(3)
    Global.res # 16

    a <- 1:4
    assign("a[1]", 2)
    a[1] == 2          # FALSE
    get("a[1]") == 2   # TRUE

[Package base version 3.1.2 Index]