javscript remove a property

 var person = {
        name: "Harry",
        age: 16,
        gender: "Male"
    };
    
    // Deleting a property completely
    delete person.age;
    alert(person.age); // Outputs: undefined
    console.log(person); // Prints: {name: "Harry", gender: "Male"}var myObject = {
    "name": "jon",
    "gender": "male",
    "registered": "yes"
};
delete myObject.gender;

console.log(myObject);

//other methods
delete myObject.gender;
// or,
delete myObject['gender'];
// or,
var prop = "gender";
delete myObject[prop];delete obj.firstname;var string = "Hello World";
var substring = "Hello";
if (string.indexOf(substring) != -1) {
  //Code here
}