JAVA classes with Instance Variable DUE IN 10 Min !!! Options

[deteam]

Write a class named ParkingMeter containing:
Two instance variables named timeLeft and maxTime of type int. The value of timeLeft should be initialized to 0.
A constructor accepting a single integer parameter whose value is used to initialize the maxTime instance variable.
A method named add that accepts an integer parameter. If the value of the parameter is equal to 25, the value of timeLeft is increased by 30; otherwise no increase is performed. Furthermore, the increase occurs only if the value of timeLeft will not exceed the value of maxTime . add returns a boolean value: true if timeLeft was increase, false otherwise.
A method named tick that accepts no parameters and returns no value. tick decreases the value of timeLeft by 1, but only if the value of timeLeft is greater than 0.
A method named isExpired that accepts no parameters. isExpired returns a boolean value: true if the value of timeLeft is equal to 0; false otherwise.

CODE

public class ParkingMeter
{

int timeLeft = 0;
int maxTime;

public ParkingMeter( int max)
{
maxTime = max ;
}

public boolean add ( int coin )
{
if ( coin == 25 )
{
if ( timeLeft +30 <maxTime )
{
timeLeft += 30;
return true;
}
}
return false;
}

public void tick()
{
if ( timeLeft > 0 )
{
timeLeft += 1;
}
}

public boolean isExpired()
{
return timeLeft == 0;
}

}

here are the errors i get

Remarks:
⇒ Your add method doesn't modify timeLeft when
the new value of timeLeft equals to maxTime
Remarks:
⇒ At Execution

Problems Detected:
⇒ isExpired() does not return the correct value

Fails When:
⇒ isExpired is false

[mipadi]

Your one line in add should read like this:

CODE

if (timeLeft + 30 <= maxTime) {

Note the <= maxTime.

Also, tick() should do this:

CODE

timeLeft--;

Note that you should decrement, not increment.