if statement with integers [duplicate]

Answer 1

if (menuNumber = 1)

should be

if (menuNumber == 1)

The former assigns the value 1 to menuNumber, the latter tests if menuNumber is equal to 1.

The reason you get cannot convert an int to boolean is that Java expects a boolean in the if(...) construct - but menuNumber is an int. The expression menuNumber == 1 returns a boolean, which is what is needed.

It's a common mix-up in various languages. I think you can set the Java compiler to warn you of other likely cases of this error.

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A trick used in some languages is to do the comparison the other way round: (1 == menuNumber) so that if you accidentally type = you will get a compiler error rather than a silent bug.

This is known as a Yoda Condition.

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In Java, a similar trick can be used if you are comparing objects using the .equals() method (not ==), and one of them could be null:

if(myString.equals("abc"))

may produce a NullPointerException if myString is null. But:

if("abc".equals(myString))

will cope, and will just return false if myString is null.

Answer 2

I get a red line that tells me I cannot convert an int to boolean.

Thats because = is an assignment operator. What you need to use is == operator.

Answer 3

A single equal sign is assignment: you assign value to a variable this way. use two equal signs (==) for comparison:

if ($menuNumber = 1) { 

Update: forgot dollar sign: $menuNumber