check if exists in object javascript code example
Example 1: javascript does key exist
var person={"name":"Billy","age":20}
person.hasOwnProperty("name");
person.hasOwnProperty("sex");
Example 2: how to check if object exists in javascript
if (typeof maybeObject != "undefined") {
alert("GOT THERE");
}
Example 3: test if property exists javascript
const hero = {
name: 'Batman'
};
hero.hasOwnProperty('name');
hero.hasOwnProperty('realName');
Example 4: how to check if a key exists in an object javascript
!("key" in obj)
!"key" in obj