NodeJS looping through an array and prompt - arrays

Question

I have an array of values to delete but want the user to confirm that he wants to delete the value. I plan to use the prompt Node module but don't know how to combine them in such a way that I move to the next value in the array after the user has confirmed (or not) the deletion of the current value. In short, the following code won't work:
var arr = ["1","2","3"];
for (var i in arr) {
console.log("Delete " + arr[i] + "?");
prompt.get(['response'], function (err, result) {
console.log(' reponse: ' + result.response);
// if ...
});
}
Any idea? Many thanks.

Answer 1

#user1280859 is right about the issue but maybe it is better to take adventage of prompt features instead of recursion or asyncronous loop:
var prompt = require('prompt');
prompt.start();
var arr = ["1","2","3"];
var promptArr = arr.map(function(num) {
return "Delete " + num + "?";
});
prompt.get(promptArr, function (err, result) {
console.log(result);
});
OutPut:
prompt: Delete 1?: y
prompt: Delete 2?: n
prompt: Delete 3?: y
{ 'Delete 1?': 'y', 'Delete 2?': 'n', 'Delete 3?': 'y' }

Answer 2

Your code is not working because you're trying to use async calls prompt.get within syncronous loop for.
In case you have to make async calls you should to wait its callbacks. Particulary in your case you can use something like
function removeEl(idx, arr, done){
if(idx>=arr.length) return done(arr);
prompt.get(['response'], function (err, result) {
console.log(' reponse: ' + result.response);
if(/*user said yes*/){
arr.splice(idx, 1);
removeEl(idx, arr, done)
}else{
removeEl(idx+1,arr, done)
}
});
}
function removeWithPrompt(arr, done){
removeEl(0, arr, done);
}
removeWithPrompt([1,2,3], function (modified) {
// modified contains non-deleted elements
})
Or use asyncronous loops like async.each