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Mathematica Teacher's Edition

Built-in Functions

System Interface

External Commands

Memory Usage

LeafCount

LeafCount[expr] gives the total number of indivisible subexpressions in expr.

LeafCount gives a measure of the total "size" of an expression.
LeafCount counts the number of subexpressions in expr which correspond to "leaves" on the expression tree.
Example: LeafCount[1 + a + b^2].
LeafCount is based on FullForm representation of expressions.
Numbers with heads Rational and Complex are treated as composite objects, just as in FullForm.
See The Mathematica Book on the web: Section 2.13.4.
See also: ByteCount, Length, AtomQ.

Further Examples