In Python, the ‘+’ operator can be used with numbers and with strings. What is a property that number addition has, but string concatenation does not?

Answered below

Explanation:

The property in number addition that is not found in string concatenation, although both use the '+' operator, is that in number addition, the expression value does not depend on the order of the numeric addition operands. Any order of arrangement of the operands produces the same value when they are added.

This is not so in string concatenation because different orders or the arrangement of different strings on concatenation, produce different results or values. For instance, the concatenation of 'He is a' + 'boy' results in 'He is a boy' whereas reversing the placements of both strings would result in a totally different value. This is not so in number addition where 4 + 2 gives the same value as 2 + 4.

Therefore the use of the '+' operator with string concatenation and with numerical additions produce different expression values where one depends on the order and one does not.