JSFiddle - React, Tailwind, and code Playground
JavaScript
var obj = {
a: undefined,
b: null,
c: false
};
if(obj.hasOwnProperty('a')) {
console.log("has a");
}
if(obj.hasOwnProperty('b') && obj['b'] !== null) {
console.log("has b");
}
if(obj.hasOwnProperty('c')) {
console.log("has c");
}
if(obj.hasOwnProperty('d')) {
console.log("has d");
}