Nested For Loops

Hi, I am using an LCD, I am a true novice, the code below is supposed to print hash characters to all the cells on the screen, it will work if I comment out either one of the loops, and add int x=0, or int y=0 where appropriate, but not as it is…Atghhhhh!!

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,2,1,0,4,5,6,7,3,POSITIVE);

void setup() {

lcd.begin(20,4);

}

void loop() {

for (int y; y<4; y++){
for (int x; x<20; x++){

lcd.setCursor(x,y);
lcd.print("#");
delay(200);

}
}
delay(200);
lcd.clear();
}

for (int y = 0; y<4; y++){
for (int x = 0; x<20; x++){

Please remember to use code tags when posting code.

Develop good habits from the start. Use a standard indentation to clearly show the code blocks. Place any brackets by themselves on a separate line. Use blank lines sparingly, no more than one at a time. Before posting the code, use Ctrl-T in the IDE to reformat the code in a standard format.

Thank you, I will try it later......still learning.