Getter
Getter methods are used to return an object's properties.
See the examples below:
const person = {
name: 'Bello',
age: 27,
getPerson() {
if (typeof this.name === 'string' && typeof this.age === 'number') {
return `${this.name} is ${this.age} years old!`;
}
return "Name or age is invalid";
}
}
console.log( person.getPerson() );
We can add a little more get keyboard to the code snippet above.
const person = {
name: 'Bello',
age: 27,
get getPerson() {
if (typeof this.name === 'string' && typeof this.age === 'number') {
return `${this.name} is ${this.age} years old!`;
}
return "Name or age is invalid";
}
}
console.log(person.getPerson); // No parenthesis used
The difference is when the get keyword was used, no parenthesis was used in the calling function.
getPerson, notgetPerson()."
The name property
A function in on object looks like a property when the get keyword is used.
See the example:
const sayHi = {
get name() {
return "Hello World!";
}
};
sayHi.name; // "Hello World!"
The syntax above looks like object.property syntax.
We can get the name of a function with the name property.
See the example below:
function greet() {
return "Hello World!";
}
console.log(greet.name); // greet
A function name can also be accessible even if used as a default parameter in another function.
function func(greet = function() {}) {
console.log(greet.name); // greet
}
func();
The length property
The length or the number of parameters of a function can also be accessible by the length property.
See the example below:
const func = (name, age) => {
return "${name} is ${age} today!";
}
console.log(func.length); // 2
Setter
Setter methods are used to set or reassign values of existing properties within an object.
const person = {
name: 'Bello',
age: 27
}
person.name = 'John';
console.log(person.name) // John;
We can do more than the example above by checking if certain properties exist in an object.
In the example below, an existing property gets reassigned
const person = {
name: 'Bello',
set setPerson(name) {
if (this.name) {
this.name = name;
} else {
console.log("Give a valid name");
}
}
};
person.setPerson = 'John';
console.log(person.name, typeof person.name) // John string
Happy coding!!!
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