"Binary "x" is the repetition operator. In scalar context or if the left
operand is not enclosed in parentheses, it returns a string consisting
of the left operand repeated the number of times specified by the right
operand.
Binary "+" returns the sum of two numbers."

"x" will not return anything because it's not given "number of times" so the same but readable:

print 1 x $anything_not_a_number
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Please, see perldoc perlop.