How to connect to the AP in loop() in ESP8266 - arduino

Question

I have an issue with WiFi.begin() in esp8266-12F.
I'm going to connect the ESP8266 with the specific Access Point in the loop() not in the setup().
I want if a specific AP is available, ESP8266 would connect to it.
In the below code, I supposed to connect to the "abc" AP and turns on an LED and if there is no connection, it turns the LED off, but WiFi.begin("abc", "123456789"); is not working.
What I have to do in this case?
setup(){
}
loop(){
if (WiFi.status() != WL_CONNECTED){
WiFi.disconnect();
WiFi.mode(WIFI_STA);
WiFi.begin("abc", "123456789");
digitalWrite(5, HIGH);
} else {
digitalWrite(5, LOW);
}
}

Answer 1

No point in adding WiFi-disconnect() if you're not connected to any AP at the moment. Just connect to the AP on the setup and leave on the loop() the if (WiFi.status() != WL_CONNECTED). The ESP reconnects itself to the AP when available.
setup(){
Serial.begin(115200);
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
WiFi.setAutoConnect(true);
Serial.print("Connecting to ");
Serial.print(ssid);
int attempt = 0;
while(WiFi.status() != WL_CONNECTED && attempt<150){ //Connecting to Wi-Fi
delay(100);
Serial.print(".");
attempt++;
}
if(WiFi.status() == WL_CONNECTED){
Serial.println("");
Serial.println("WiFi Connected!");
Serial.print("Local IP: ");
Serial.println(WiFi.localIP());
}
if(attempt == 150){
Serial.println("Failed to connect to WiFi...");
}
}
loop(){
if(WiFi.status() != WL_CONNECTED){
digitalWrite(5,HIGH);
}else{
digitalWrite(5,LOW);
}
}
But for the love of good code otimization use a flag to prevent the digitalWrite to happen hundreds of times per second

Answer 2

I would use the standard code for building a WiFi connection in the setup() and just set the led as HIGH/LOW in the loop() according to WiFi.status(). Reconnect should be handled automatically...