¿Cómo se elimina un valor indefinido de un objeto?

How do you remove an undefined value from an object?

delete obj[key] : {}); Or use short-circuit evaluation instead of ternary: (@Matt Langlois, thanks for the info!) Note that the identity function is just x => x and its result will be false for all falsy values. So this removes undefined, “”, 0, null.

undefined if they are passed as values to the method. null if they are passed as an array element. nothing if passed as properties on an object. throws an error if its an object with circular references(s) on it.

2 Answers

1. undefined is not a valid JSON value, even though it is valid in javascript. From the official JSON standard (ECMA-404, Section 5): A JSON value can be an object, array, number, string, true, false, or null.
2. For JSON, use null instead of undefined: { “something”: null }

To remove JSON element, use the delete keyword in JavaScript.

If we want to filter out all the falsy values (such as 0 or null) we can use return !! element; instead. data = data. filter( Boolean );

JSON Manipulation with Javascript

1. Basic.
2. Object and string conversion.
3. Loop through JSON Objects.
4. Loop through JSON Arrays.
5. Read a JSON tree recursively.
6. Get keys, values of an object.
7. Convert a http response to object.
8. Merge two jsons, or say values overwriting.

undefined , Function s, and Symbol s are not valid JSON values. If any such values are encountered during conversion they are either omitted (when found in an object) or changed to null (when found in an array).

JSON.stringify () seems to do exactly what you need. It will remove all functions and all undefined variables. If you need the object itself, you can JSON.parse the resulting string to go back to a clean object. Thanks for contributing an answer to Code Review Stack Exchange!

In this article, I will show you remove empty object in json in javascript. If you want to remove all empty object then you can use this soltution. I will give you easy and simple example of remove null values in json using javascript. I just created one simple html file. so you can understand to remove all null values in javascript.

Use jQuery to copy non-null properties to an empty object. No deep copy unless you add true as first argument. Mhh.. I think @Damian asks for remove undefined field (property) from an JS object. Then, I would simply do :

While running JSON code like the one shown below, older browsers like IE7 produces the error – ‘JSON’ is undefined: The error occurs while executing the JSON.parse () method by older browsers that have not implemented the JSON object. The solution to this error is to download the json2 library and include it in your script, as shown below:

How to remove empty objects from an array in JavaScript

1. Iterate through an array of objects using Array.filter method and,
2. In each iteration check if the object is empty inside the callback function.

Undefined is also a primitive value in JavaScript. A variable or an object has an undefined value when no value is assigned before using it. So you can say that undefined means lack of value or unknown value.

In a JavaScript program, the correct way to check if an object property is undefined is to use the typeof operator . typeof returns a string that tells the type of the operand. It is used without parentheses, passing it any value you want to check:

There is only one JavaScript statement in function body which instructs to return the argument (n) of the function after multiply by itself twice. Here the return statement returns the calculated value. Use function declarations instead of function expressions as function declarations are named, so they’re easier to identify in call stacks.

No; Javascript functions are not required to return a value. If you call a function that doesn’t return a value, you’ll get undefined as the return value. Same goes for functions that has return; in them. And functions that can exit with out executing one of its returns.