Arduino LED flashes with one button press

Question

I want the LED to flash when I press the switch once, but it keeps flashing. I tried the idea of just lighting the LED and keeping it lit with just one button press, so I wrote:

int led=13,button=12;
void setup() {
pinMode(led,OUTPUT);
pinMode(button,INPUT);
}
void loop() {
if (digitalRead(button)==HIGH)
  digitalWrite(led,HIGH);
}

and this worked; it stayed on after I pressed the button once, so for the flashing LED I wrote:

int led=13,button=12;
void setup() {
pinMode(led,OUTPUT);
pinMode(button,INPUT);
}
void loop() {
if (digitalRead(button)==HIGH)
{
  digitalWrite(led,HIGH);
delay(1000);
 digitalWrite(led,LOW);
 delay(1000);

} }

but this didn't work. It stops flashing after I remove my hand from the switch. Why is this happening?

Answer 1

Because the digital writes only apply on if (digitalRead(button)==HIGH). If you don't press the button, then the code goes:

void loop() {
}

Essentially doing nothing. Your code needs a bit more to keep track of the button press. Pseudo Code:

if button == pressed {
    int tracker=1;
}
if tracker == 1 {
    led on;
    wait;
    led off;
    wait;
}
loop

Answer 2

This is what you need. When you pressed the button then your LED turn ON. And it still ON until you pressed the button again.I hope it will help you.

const int kPinBtn = 2;
const int kPinLed = 13;

boolean kPress = false;

void setup()
{
  pinMode(kPinBtn, INPUT_PULLUP);
  pinMode(kPinLed, OUTPUT);
}

void loop()
{
  if(digitalRead(kPinBtn) == LOW && kPress == false)
  {
    digitalWrite(kPinLed, HIGH);
    kPress = true;
  }
  if(digitalRead(kPinBtn) == LOW && kPress == true)
  {
    digitalWrite(kPinLed, LOW);
    kPress = false;
  }  
}