Question

void doSomething(int num)

Which of the following would be valid ways to invoke this method?

答案选项组

System.out.println(doSomething(5));

doSomething("word".length());

doSomething(4);

doSomething(int);

doSomething(4.0);

doSomething(Math.random());

doSomething(7 + 5);

int answer = doSomething(5);

double result = doSometing(23);

doSomething((int)Math.PI);

Answer 1

Explanation:

All of the above mentioned methods are invalid because doSomething() is an instance method , so it must be invoked by object.

// Screenshot of the code & Errors output

// Screenshot of the Correct code & output

After creating object and invoking method with object(d) following 4 valid methods are below.

       d.doSomething("word".length());

       d.doSomething(4);

d.doSomething(7 + 5);

d.doSomething((int)Math.PI);