Replaces the entire expression (or a specific level) using a rule.
Replace[expr, rules]
Replace[expr, rules, levelspec]
Replace[rules]
Replace[x + y, x -> a]
→ x + yReplace[{1, 2, 3}, x_ -> x^2, {1}]
→ {1, 4, 9}Replace[x, b]
→
Replace::reps: {b} is neither a list of replacement rules nor a valid dispatch table and so cannot be used for replacing.
Replace[x, b]