JavaScript - Qualification Test (Senior) > Closures

UnderstandingClosures.js

function init(list)
{
  var result = [ ];
  
  for (var i=0; i<list.length; i++)
  {
     var item = 'item' + list[i];
     
    result.push( function() {
      console.log( item + ' ' + list[i]);   
    });

  }
  return result;
}

function foo() 
{
  var list = init([1,2,3]);
  for ( var j=0; j<list.length; j++)
  {
    list[j]();
  }
}

foo();

Question: What does foo() print to the console?

Question: How would you fix it to log
item1 1
item2 2
item3 3

// Code goes here

function init(list)
{
  var result = [ ];

  for (var i=0; i<list.length; i++)
  {
     var item = 'item' + list[i];
     result.push( makeLogger(i, item) );
  }
  return result;

  // Capture the parameters for future logging
  function makeLogger(i, item)
  {
    return function() {
        console.log( item + ' ' + list[i]);   
    }; 
  }  
}

function foo() 
{
  var list = init([1,2,3]);
  for ( var j=0; j<list.length; j++)
  {
    list[j]();
  }
}

foo();