In TypeScript, we can use get/set to define a property in the class. This property can be accessed using a getter and a setter function.
Here's an example:
class Person {
private _age: number;
get age(): number {
return this._age;
}
set age(value: number) {
if (value < 0) {
console.error('Age can not be negative');
} else {
this._age = value;
}
}
}
const john = new Person();
john.age = -10; // outputs 'Age can not be negative' to console
john.age = 20; // sets john's age to 20
console.log(john.age); // logs 20 to console
In the example above, we have defined a private property _age and a public property age using get/set. When we set the value of age, it triggers the set function, which checks whether the value is negative or not. If it is negative, it outputs an error message to the console. If not, it sets the value of _age. When we get the value of age, it triggers the get function, which simply returns the value of _age.