atom_number/2

defines a relation between an atom and a number.

atom_number(-Atom, +Number)
atom_number(+Atom, ?Number)

If Atom is an atom which is parseable as number, then Number will be unified with the value of that number.
If Atom is a variable, then Number must be a number. atom_number/2 will unify Atom with the textual representation of the Number.

Arguments 

Atom                  atom
Number                number

Examples

atom_number(X,2.3). Succeeds with substitution X <- '2.3'
atom_number('3',Y). Succeeds with substitution Y <- 3.
atom_number('12',12). Succeeds.
atom_number(X,Y). instantiation_error.

Standard

This predicate is not part of the ISO-Prolog Standard.

See also

atom_chars/2, atom_codes/2, atom_concat/3, atom_length/2, char_code/2, number_chars/2, number_codes/2, parse_atom/2/3, sub_atom/5.

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