How to delete Object Property without knowing its Key. JavaScript

What you can do is get the keys of your object and then delete them according to the index that you want, for example the first key (index: 0), the third (index: 2), etc.

var pasada = {
             "09-10" : 34.11,
             "09-11" : 35.73,
             "09-12" : 34.03,
             "09-13" : 35.85,
             "09-14" : 38.75,
             "09-15" : 34.07,
             "09-16" : 32.46,
             "09-17" : 34.57
              };
              
var keys = Object.keys(pasada);
var indexKeyToDelete = 0;

console.log("El objeto con todas las keys:");
console.log(pasada);

// Equivale a "delete pasada.NombreDeLaKey" o "delete pasada["NombreDeLaKey"]"
delete pasada[keys[indexKeyToDelete]];

console.log("El objeto con la key borrada:");
console.log(pasada);

Additional information:

  

Object.keys returns an array whose elements are strings   corresponding to the enumerable properties that are found   directly on the object.

     

The delete operator removes a property from an object.

You can get the keys like this:

var llaves = Object.keys(pasada);

As a result I would give you an arrangement:

[09-10, 09-11, ... ]

Now that you have the keys you can play whatever you want

var llave = llaves[0]; // Es la primera

var llave = llaves[llaves.length - 1]; // es la ultima

And you can occupy this arrangement to make an indeterminate number of combinations.

• Get the pairs or odd
• Get the ones that start on 9
• etc.

Now that you know the key, just erase it

delete pasada[llave];