Here's a version that compiles:
#include <Adafruit_NeoPixel.h>
#define BUTTON_PIN 2  // Digital IO pin connected to the button. This will be
// driven with a pull-up resistor so the switch should
// pull the pin to ground momentarily. On a high -> low
// transition the button press logic will execute.
#define PIXEL_PINÂ Â 6Â // Digital IO pin connected to the NeoPixels.
#define PIXEL_COUNT 24Â // number of neopixel (change this accordingly)
// Parameter 1 = number of pixels in strip, neopixel stick has 8
// Parameter 2 = pin number (most are valid)
// Parameter 3 = pixel type flags, add together as needed:
//Â NEO_RGBÂ Â Pixels are wired for RGB bitstream
//Â NEO_GRBÂ Â Pixels are wired for GRB bitstream, correct for neopixel stick
//Â NEO_KHZ400Â 400 KHz bitstream (e.g. FLORA pixels)
//Â NEO_KHZ800Â 800 KHz bitstream (e.g. High Density LED strip), correct for neopixel stick
Adafruit_NeoPixel strip = Adafruit_NeoPixel(PIXEL_COUNT, PIXEL_PIN, NEO_GRB + NEO_KHZ800);
bool oldState = HIGH;
int showType = 0;
void setup()
{
 pinMode(BUTTON_PIN, INPUT_PULLUP);
 strip.begin();
 strip.setBrightness(100); // Lower brightness and save eyeballs!
 strip.show(); // Initialize all pixels to 'off'
}
void loop()
{
 // Some example procedures showing how to display to the pixels:
 colorWipe(strip.Color(0, 0, 0), 50);  // Black
 colorWipe(strip.Color(255, 255, 255), 50); // White
 colorWipe(strip.Color(0, 100, 0), 50); // Green
 colorWipe(strip.Color(255, 165, 0), 50); // Orange
 colorWipe(strip.Color(255, 0, 0), 50); // Red
 colorWipe(strip.Color(0, 0, 255), 50); // Blue
 rainbow(20);
 rainbowCycle(20);
 theaterChaseRainbow(50);
 // Get current button state.
 bool newState = digitalRead(BUTTON_PIN);
 // Check if state changed from high to low (button press).
 if (newState == LOW && oldState == HIGH)
 {
  // Short delay to debounce button.
  delay(20);
  // Check if button is still low after debounce.
  newState = digitalRead(BUTTON_PIN);
  if (newState == LOW)
  {
   showType++;
   if (showType > 9)
    showType = 0;
   startShow(showType);
  }
 }
 // Set the last button state to the old state.
 oldState = newState;
}
void startShow(int i)
{
 switch (i)
 {
  case 0: colorWipe(strip.Color(0, 0, 0), 50);  // Black/off
   break;
  case 1: colorWipe(strip.Color(255, 255, 255), 50); // White
   break;
  case 2: colorWipe(strip.Color(0, 100, 0), 50); // Green
   break;
  case 3: colorWipe(strip.Color(255, 165, 0), 50); // Orange
   break;
  case 4: colorWipe(strip.Color(255, 0, 0), 50); // Red
   break;
  case 5: colorWipe(strip.Color(0, 0, 255), 50); // Blue
   break;
  case 6: rainbow(20);
   break;
  case 7: rainbowCycle(20);
   break;
  case 8: theaterChaseRainbow(50);
   break;
 }
}
// Fill the dots one after the other with a color
void colorWipe(uint32_t c, uint8_t wait)
{
 for (uint16_t i = 0; i < strip.numPixels(); i++)
 {
  strip.setPixelColor(i, c);
  strip.show();
  delay(wait);
 }
}
void rainbow(uint8_t wait)
{
 uint16_t i, j;
 delay(1000);
 while (true)
 {
  for (j = 0; j < 256; j++)
  {
   for (i = 0; i < strip.numPixels(); i++)
   {
    strip.setPixelColor(i, Wheel((i + j) & 255));
    if(digitalRead(BUTTON_PIN)==LOW)
     {
     delay(1000);
     return;
     }
   }
   strip.show();
   delay(1000);
  }
 }
}
// Slightly different, this makes the rainbow equally distributed throughout
void rainbowCycle(uint8_t wait)
{
 uint16_t i, j;
 for (j = 0; j < 256 * 5; j++) // 5 cycles of all colors on wheel
 {
  for (i = 0; i < strip.numPixels(); i++)
  {
   strip.setPixelColor(i, Wheel(((i * 256 / strip.numPixels()) + j) & 255));
  }
  strip.show();
  delay(wait);
 }
}
//Theatre-style crawling lights with rainbow effect
void theaterChaseRainbow(uint8_t wait)
{
 for (int j = 0; j < 256; j++)  // cycle all 256 colors in the wheel
 {
  for (int q = 0; q < 3; q++)
  {
   for (int i = 0; i < strip.numPixels(); i = i + 3)
   {
    strip.setPixelColor(i + q, Wheel( (i + j) % 255)); //turn every third pixel on
   }
   strip.show();
   delay(wait);
   for (int i = 0; i < strip.numPixels(); i = i + 3)
   {
    strip.setPixelColor(i + q, 0);   //turn every third pixel off
   }
  }
 }
}
// Input a value 0 to 255 to get a color value.
// The colours are a transition r - g - b - back to r.
uint32_t Wheel(byte WheelPos)
{
 if (WheelPos < 85)
 {
  return strip.Color(WheelPos * 3, 255 - WheelPos * 3, 0);
 }
 else if (WheelPos < 170)
 {
  WheelPos -= 85;
  return strip.Color(255 - WheelPos * 3, 0, WheelPos * 3);
 }
 else
 {
  WheelPos -= 170;
  return strip.Color(0, WheelPos * 3, 255 - WheelPos * 3);
 }
}
