Keypad 4*4 with Arduino - if-statement

Question

I am using keypad 4*4 with an Arduino Mega, I have sensors connected to the Arduino I want to press a key from the keypad and have response in the same time, I don't want to wait till the loop continue, I want to save up to 10 numbers entered from the keypad, so is there a way to make the keypad as an interrupt for my code?
void loop()
{
char key = kpd.getKey();
if (key != NO_KEY) {
if (key == 'C') //clear the array
{
index = 0;
numbers[index] = '\0';
}
else if (key == '.') {
numbers[index++] = '.';
numbers[index] = '\0';
}
else if (key >= '0' && key <= '9') {
for (int z = 0; z == 10; z++) {
numbers[index++] = key;
numbers[index] = '\0';
}
}
else if (key == 'A') {
float len = atof(numbers); //conversion from string to numeric
if (fona.callPhone(numbers)) {
Serial.println(F("RING!"));
Serial.print(F("Phone Number: "));
Serial.println(numbers); //print out on serial monitor
}
}
else if (key == 'D') {
if (fona.pickUp()) {
Serial.println(F("Failed"));
}
}
else if (key == '#') {
if (fona.hangUp()) {
Serial.println(F("Failed"));
}
}
}
gas = analogRead(gasPin);
dtostrf(gas, 4, 2, gass);
Serial.println(gas);
delay(1000); // Print value every 1 sec.
val = digitalRead(inputPin); // read input value
if (val == HIGH) { // check if the input is HIGH
digitalWrite(ledPin, HIGH); // turn LED ON
delay(150);
if (pirState == LOW) {
// we have just turned on
Serial.println("Motion detected!");
// We only want to print on the output change, not state
pirState = HIGH;
}
}
else {
digitalWrite(ledPin, LOW); // turn LED OFF
delay(300);
if (pirState == HIGH) {
// we have just turned off
Serial.println("Motion ended!");
// We only want to print on the output change, not state
pirState = LOW;
}
}
int ldrStatus = analogRead(ldrPin);
if (ldrStatus <= 550) {
digitalWrite(led, HIGH);
Serial.println("LDR is DARK, LED is ON");
}
else {
digitalWrite(led, LOW);
}
valee = analogRead(tempPin);
float cel = (valee * 0.48828125) / 2.12304;
dtostrf(cel, 4, 2, temp);
Serial.print("TEMPRATURE = ");
Serial.print(cel);
Serial.print("*C");
Serial.println();
delay(1000);