Help with understanding setup in classes!

I'm having trouble with understanding the setup in my class. Could someone please explain me the reason behind giving 3 names to the same LED?

Here is my header:

class alarmLight {
public:
alarmLight(int pin_gre_1, int pin_gre_2, int pin_yel_1, int pin_yel_2, int pin_red, int pin_speaker);

functions etc.

void setup(int pinLed_gre_1, int pinLed_gre_2, int pinLed_yel_1, int pinLed_yel_2, int pinLed_red, int pin_SPEAKER);

private:
int led_gre_1;
int led_gre_2;
int led_yel_1;
int led_yel_2;
int led_red;
int speaker;
};

The cpp:

alarmLight::alarmLight(int pin_gre_1, int pin_gre_2, int pin_yel_1, int pin_yel_2, int pin_red, int pin_speaker) {
setup(pin_gre_1, pin_gre_2, pin_yel_1, pin_yel_2, pin_red, pin_speaker);

void alarmLight::setup(int pinLed_gre_1, int pinLed_gre_2, int pinLed_yel_1, int pinLed_yel_2, int pinLed_red, int pin_SPEAKER) {
led_gre_1 = pinLed_gre_1;
led_gre_2 = pinLed_gre_2;
led_yel_1 = pinLed_yel_1;
led_yel_2 = pinLed_yel_2;
led_red = pinLed_red;
speaker = pin_SPEAKER;

pinMode(led_gre_1, OUTPUT);
pinMode(led_gre_2, OUTPUT);
pinMode(led_yel_1, OUTPUT);
pinMode(led_yel_2, OUTPUT);
pinMode(led_red, OUTPUT);
pinMode(speaker, OUTPUT);
}

To make it clear to the forum, post the three names you think are the same. They all look unique to me.

Folks appreciate it when you use code tags:

If I understand your question:

The first is the name of the class.

The third one is the class constructor definition. It runs whenever you instantiate an instance of the class. It always has the same name as the class.

The second one is the function prototype of the class constructor. It gets the compiler ready to deal with the constructor definition.