(Julia) Not able suppress output using semicolon when assigning variable inside an IF statement

Why does adding a semicolon in an IF ELSE statement is unable to suppress the output display?

Unable to suppress output

Indeed as the Julia Manual explains:

If an expression is entered into an interactive session with a trailing semicolon, its value is not shown.

However, this statement refers to the whole entered expression. In your case the whole expression includes the if part so you should write:

if condition
    ...
else
    ...
end;

(note the semicolon afer end)

In particular note, as explained here in the Julia Manual, that:

if blocks also return a value, which may seem unintuitive to users coming from many other languages. This value is simply the return value of the last executed statement in the branch that was chosen

Putting ; after end suppresses printing of the value returned by the if block.