This is documentation for Mathematica 5, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.1)

Documentation / Mathematica / Built-in Functions / Programming / Rule Application /

ReplaceAll

FilledSmallSquare expr /. rules applies a rule or list of rules in an attempt to transform each subpart of an expression expr.

FilledSmallSquare Example: x + 2 /. x -> a LongRightArrow.

FilledSmallSquare ReplaceAll looks at each part of expr, tries all the rules on it, and then goes on to the next part of expr. The first rule that applies to a particular part is used; no further rules are tried on that part, or on any of its subparts.

FilledSmallSquare ReplaceAll applies a particular rule only once to an expression.

FilledSmallSquare Example: x /. x -> x + 1 LongRightArrow.

FilledSmallSquare See the notes on Replace for a description of how rules are applied to each part of expr.

FilledSmallSquare expr /. rules returns expr if none of the rules apply.

FilledSmallSquare See Section 2.5.1.

FilledSmallSquare See also: Rule, Set, MapAll, ReplaceRepeated, TransformationFunctions.

FilledSmallSquare New in Version 1.

Further Examples