Java相当于Ruby的`if condition`代码

Question

This has probably been asked before but I can't seem to find anything useful in Google (probably I'm looking for it wrong) nor here.

What is the equivalent (if there actually is one) of Ruby's code if condition in Java?

Example in Ruby (taken from TutorialsPoint):

$debug=1
print "debug\n" if $debug

In Java instead of doing

if (conditional) {
    doSomething();
}

I'd like to do something like

doSomething() if (conditional);

If I do

if (conditional) doSomething();

I get a warning with a suggestion to invert if.

Answer 1

You cannot do that in Java, it isn't legal syntax.

You can do,

if (conditional) doSomething();

or

if (conditional) {
    doSomething();
}

or even change the signature of doSomething() to take a boolean and then

doSomething(conditional);

but you cannot add your desired syntax to the language without writing a pre-compiler.

For more see JLS-14.9. The if Statement .

Answer 2

There is no equivalent. Ruby's statement is more syntactic sugar than anything else, as you can write the if statement in the same manner as you would in Java.

For Java, you're stuck wrapping your expressions in if statements:

if(conditional) {
    takeAction();
}