ES6 Classes & Constructors

What programming pattern is demonstrated by the Calculator class?

class Calculator {
  constructor() {
    this.value = 0;
  }
  
  add(a) {
    this.value += a;
    return this;
  }
  
  subtract(a) {
    this.value -= a;
    return this;
  }
  
  getValue() {
    return this.value;
  }
}

Factory pattern
Module pattern
Method chaining
This class implements the method chaining pattern: 1) Each method returns 'this' (the class instance itself), 2) This allows multiple method calls to be chained together in a single statement, 3) Enables fluent interfaces for more readable code, 4) Commonly used in builder patterns and query builders, 5) Improves code expressiveness and reduces variable declarations, 6) Makes the API more intuitive for operations that build on each other.
Singleton pattern

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