class Calculator
{
// instance variables - replace the example below with your own
private double result;

/**
* Constructor for objects of class Calculator
*/
public Calculator()
{
// initialise instance variables
result = 0;
}

public double add( double value)
{
// put your code here
return result+=value;
}
public double subtract( double value)
{
// put your code here
return result-=value;
}
public double multiplyBy( double value)
{
// put your code here
return result*=value;
}
public double divideBy( double value)
{
// put your code here
if(value==0.0)
return result;//can not divide by 0, returning last result
else
return result/=value;
}
public double clear()
{
// put your code here
return result=0;
}
}

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