JAVA

import static java.lang.System.out;

enum ScaleName {celsius, fahrenheit, kelvin, rankine};

class Temperature()
{
    private double number;
    private ScaleName scale;

    public Temperature()
    {
        number = 0.0;
        scale = ScaleName.fahrenheit;
    }

    public Temperature(double number)
    {
        this.number = number;
        scale = ScaleName.fahrenheit;
    }

    public Temperature(double number, ScaleName scale)
    {
        this.number = number;
        this.scale = scale;
    }

    public void setNumber(double number)
    {
        this.number = number;
    }

    public double getNumber()
    {
        return number;
    }

    public void setScale(ScaleName scale)
    {
        this.scale = scale;
    }
    public ScaleName getScale()
    {
        return scale;
    }
}

//Rest of the code...

error = '{' expected line 5

why.jpg

class Temperature() ≠ class Temperature

Just remove the().