Resumo/Informações
- Data Structure
Maps possui a mesma ideia de objetos, porém com muito mais recursos.
Possível de se utilizar:
- forEach (porque está no prototype de maps).
- Anything as keys, como strings, booleans, etc.
- They are iterable, making it easy to loop through them and to manipulate data with them.
- Easy to get the size of a map using the size property.
- Easily add and remove data from a map.
- Example
const question = new Map();
question.set('question', 'What is the official name of the latest major JavaScript version?');
question.set(1, 'ES5'); Esses 1, 2, 3, 4 são Choice elements
question.set(2, 'ES6');
question.set(3, 'ES2015');
question.set(4, 'ES7');
question.set('correct', 3);
question.set(true, 'Correct answer :D');
question.set(false, 'Wrong, please try again!');
console.log(question.get('question')); Irá dar print no elemento que possui question no primeiro Choice element.
//console.log(question.size);
if(question.has(4)) {
//question.delete(4); Used to delete a question
console.log('Answer 4 is here'); Se existir a question 4, isso ocorre
}
// question.clear(); clears everything, deletes it all
// forEach example, onde todos os elementos são utilizados.
question.forEach((value, key) => console.log(`This is ${key}, and it's set to ${value}`));
O forEach passa em cada elemento do maps, recupera as informações value e key deles e então as utiliza na proxima ordem, nesse caso o console.log
for (let [key, value] of
question.entries()) {
if (typeof(key) === 'number') {
console.log(`Answer ${key};
${value}`);
}
}
const ans = parseInt(prompt('Write the correct answer'));
console.log(question.get(ans === question.get('correct'))); Compara a answer com a true answer, então se o input for o mesmo que a correct answer, isso será true