weird array behaviour in javascript [duplicate]

by

This behaviour isn’t limited to arrays, any object behaves this way in the console

What you are seeing is the result of console in all browsers “lying” to you

if you console.log(anyobject) and inspect that object in the console, what you will see is current anyobject – not what it was when console.log was executed

var obj = {}
console.log(obj);
obj.test = 1;

var arr = [1];
console.log(arr);
arr.push(2);

Now, if you open the developer console, click on the Object, you’ll see test:1

Look at the array in the console – it is output as [1] … yet, click on the array you see both elements

Note: chrome developer console does at least hint at the fact that it’s lying to you – there’s a blue i, if you hover (or click, can’t recall, don’t use Chrome often enough) you’ll see a message saying that the value shown is evaluated just now

More Related Contents:

  1. Filter JSON by key value with JavaScript
  2. fetch first element of every string in array using javascript [closed]
  3. Convert string into several integer arrays [duplicate]
  4. Accesing 2d arrays from Javascript [closed]
  5. How to remove all duplicates from an array of objects?
  6. Determine whether an array contains a value [duplicate]
  7. Best way to find if an item is in a JavaScript array? [duplicate]
  8. Most efficient way to create a zero filled JavaScript array?
  9. Sort array of objects by single key with date value
  10. What is “undefined x 1” in JavaScript?
  11. Check if an array is empty or exists
  12. Why Array.indexOf doesn’t find identical looking objects
  13. How to count the number of occurrences of each item in an array? [duplicate]
  14. JavaScript – why Array.prototype.fill actually fills a “pointer” of object when filling anything like ‘new Object()’
  15. Convert object array to hash map, indexed by an attribute value of the Object
  16. Check if array contains all elements of another array
  17. How to convert array into string without comma and separated by space in javascript without concatenation?
  18. JavaScript arrays braces vs brackets
  19. Convert object to array of key–value objects like `{ name: “Apple”, value: “0.6” }`
  20. Sort array containing objects based on another array [duplicate]
  21. How to find index of an object by key and value in an javascript array
  22. jQuery min/max property from array of elements
  23. traversing through JSON string to inner levels using recursive function
  24. remove item from array using its name / value
  25. Do loops check the array.length every time when comparing i against array.length?
  26. Get largest value in multi-dimensional array javascript or coffeescript
  27. How do I unset an element in an array in javascript?
  28. javascript – match string against the array of regular expressions
  29. How to find the coordinate that is closest to the point of origin?
  30. Converting Array of Objects into Array of Arrays

Leave a Comment