value to check
true if value is an uncommon object
// Returns false for common objects
isPlainObject(new Date()) // false
isPlainObject(new RegExp('')) // false
isPlainObject(new Function()) // false
isPlainObject(new Error()) // false
isPlainObject(new Array()) // false
isPlainObject(new Set()) // false
// Returns true for uncommon objects
isPlainObject({}) // true
isPlainObject(new MyClass()) // true
Checks if value is an uncommon object. Used to determine if a value is a user defined object.