The Builder pattern is used to construct complex objects step by step. It separates the construction of a complex object from its representation, allowing the same construction process to create different representations.

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Example in ReactJS:

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Imagine you're creating a form builder that allows users to dynamically add form fields.

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// FormBuilder.js

const FormBuilder = () => {

const fields = [];

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const addTextField = (label) => {

fields.push(<input type="text" placeholder={label} />);

};

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const addCheckbox = (label) => {

fields.push(<input type="checkbox" /> <label>{label}</label>);

};

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const getResult = () => fields;

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return {

addTextField,

addCheckbox,

getResult,

};

};

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// Usage

const formBuilder = FormBuilder();

formBuilder.addTextField("Name");

formBuilder.addCheckbox("Agree to terms");

const formFields = formBuilder.getResult();