I am getting "you got undefined question(s) right." can anyone tell me whats wrong in my code

connor is right you have to set the value of correctAnswer to a number in this case to 0 and also there is a typo in your loop

for(var i=0;i<questions.length;i+=1){
  question=questions[i][0];
  answer=questions[i][1]; 
  response= parseInt(prompt(questions)); //here it should be (question) questions is actually the array
// here you are displaying the array not the questions
}

in this case this would work but when you try to parseInt() what the user types, and one of your answers is a string. so if you run this you will get 2 answers right even if you type the right answers. try using strings instead and remove the parseInt.

var questions=[
  ['how old are you?', '5'], // wrap numbers in quotation marks
  ['whats your name?', 'Jon'],
  ['how many litres of water do you drink in a day?', '4'] 
] ;

for(var i=0;i<questions.length;i+=1){
  question=questions[i][0];
  answer=questions[i][1]; 
  response= (prompt(question); // remove parseInt()
}

hope this helps

You haven't assigned a value to correctAnswer to begin with. You want the code to += 1 to correctAnswer but it doesn't have a value to += 1 to.

Try: var correctAnswer = 0;

Let me know if this works!

Thank you so much