An object literal creates an object directly from a literal expression. It is usually the quickest choice for a one-time object or for grouping related data passed to or returned from a function. section 1.2
Choose an object-creation approach according to how the objects will be used:
- Use an object literal for a single object or a small data bundle. section 1.2
- Use Object.create, a factory function, or a class when multiple objects share a shape or prototype relationship. section 1.2
- Use the spread operator or Object.assign to combine several objects into a new object. section 1.2
A literal used as a prototype
const transaction = { sender: 'luis@tjoj.com', recipient: 'luke@tjoj.com' }; const moneyTransaction = Object.create(transaction); moneyTransaction.funds = 0.0; moneyTransaction.addFunds = function addFunds(funds = 0) { this.funds += Number(funds); }; moneyTransaction.addFunds(10.0); // moneyTransaction.sender === 'luis@tjoj.com' // moneyTransaction.funds === 10 section 2.1
Listing 2.2 Transaction objects linked by a basic prototype setup
const transaction = { #1
sender: 'luis@tjoj.com',
recipient: 'luke@tjoj.com'
};
const moneyTransaction = Object.create(transaction); #2
moneyTransaction.funds = 0.0;
moneyTransaction.addFunds = function addFunds(funds = 0) { #3
this.funds += Number(funds);
}
moneyTransaction.addFunds(10.0);
moneyTransaction.funds; // 10.0
Inspect the complete transaction example, including the literal’s properties, the Object.create relationship, and the added method. section 2.1
