Array
Criação
const numbers = [1, 2, 4, 7];
console.log(numbers); //=> [ 1, 2, 4, 7 ]const numbers = [1, 2, 4, 7];
console.log(numbers); //=> [ 1, 2, 4, 7 ]const numbers = [];
numbers[0] = 10;
numbers[1] = 20;
numbers[10] = 100;
console.log(numbers); //=> [ 10, 20, , , , , , , , , 100 ]const numbers = [];
numbers[0] = 10;
numbers[1] = 20;
numbers[10] = 100;
console.log(numbers); //=> [ 10, 20, , , , , , , , , 100 ]Acesso e Alteração
const numbers = [1, 2, 4, 7];
console.log(numbers[0]); //=> 1
console.log(numbers[3]); //=> 7
console.log(numbers[4]); //=> undefined
console.log(numbers); //=> [ 1, 2, 4, 7 ]const numbers = [1, 2, 4, 7];
console.log(numbers[0]); //=> 1
console.log(numbers[3]); //=> 7
console.log(numbers[4]); //=> undefined
console.log(numbers); //=> [ 1, 2, 4, 7 ]const numbers = [1, 2, 4, 7];
// change value
numbers[2] = 5;
// add value
numbers[4] = 10;
console.log(numbers); //=> [ 1, 2, 5, 7, 10 ]
// delete value
delete numbers[4];
console.log(numbers); //=> [ 1, 2, 5, 7, ]const numbers = [1, 2, 4, 7];
// change value
numbers[2] = 5;
// add value
numbers[4] = 10;
console.log(numbers); //=> [ 1, 2, 5, 7, 10 ]
// delete value
delete numbers[4];
console.log(numbers); //=> [ 1, 2, 5, 7, ]Tipos Múltiplos
const values = [1, 'John', true, null, [1, 2]];
console.log(values[1]); //=> "John"
console.log(values[4]); //=> [1, 2]
console.log(values[4][1]); //=> 2const values = [1, 'John', true, null, [1, 2]];
console.log(values[1]); //=> "John"
console.log(values[4]); //=> [1, 2]
console.log(values[4][1]); //=> 2Spread Operator
const numbers = [1, 2, 3];
console.log([...numbers, 4, 5]); //=> [ 1, 2, 3, 4, 5 ]const numbers = [1, 2, 3];
console.log([...numbers, 4, 5]); //=> [ 1, 2, 3, 4, 5 ]Iteração
for
const numbers = [1, 2, 4];
let result = '';
for (let flag = 0; flag < numbers.length; flag++) {
result += numbers[flag] + ' ';
}
console.log(result); //=> "1 2 4 "const numbers = [1, 2, 4];
let result = '';
for (let flag = 0; flag < numbers.length; flag++) {
result += numbers[flag] + ' ';
}
console.log(result); //=> "1 2 4 "for..in
const numbers = [1, 2, 4];
let result = '';
for (const index in numbers) {
result += numbers[index] + ' ';
}
console.log(result); //=> "1 2 4 "const numbers = [1, 2, 4];
let result = '';
for (const index in numbers) {
result += numbers[index] + ' ';
}
console.log(result); //=> "1 2 4 "for..of
const numbers = [1, 2, 4];
let result = '';
for (const value of numbers) {
result += value + ' ';
}
console.log(result); //=> "1 2 4 "const numbers = [1, 2, 4];
let result = '';
for (const value of numbers) {
result += value + ' ';
}
console.log(result); //=> "1 2 4 "Objeto Array
Property: length
const numbers = [1, 2, 3];
console.log(numbers.length); //=> 3const numbers = [1, 2, 3];
console.log(numbers.length); //=> 3Mutator: push(), unshift(), pop(), shift(), reverse(), sort(), splice()
const numbers = [1, 2, 3];
console.log(numbers.push(4)); //=> 4
console.log(numbers); //=> [ 1, 2, 3, 4 ]const numbers = [1, 2, 3];
console.log(numbers.push(4)); //=> 4
console.log(numbers); //=> [ 1, 2, 3, 4 ]const numbers = [1, 2, 3];
console.log(numbers.unshift(0)); //=> 4
console.log(numbers); //=> [ 0, 1, 2, 3 ]const numbers = [1, 2, 3];
console.log(numbers.unshift(0)); //=> 4
console.log(numbers); //=> [ 0, 1, 2, 3 ]const numbers = [1, 2, 3];
console.log(numbers.pop()); //=> 3
console.log(numbers); //=> [ 1, 2 ]const numbers = [1, 2, 3];
console.log(numbers.pop()); //=> 3
console.log(numbers); //=> [ 1, 2 ]const numbers = [1, 2, 3];
console.log(numbers.shift()); //=> 1
console.log(numbers); //=> [ 2, 3 ]const numbers = [1, 2, 3];
console.log(numbers.shift()); //=> 1
console.log(numbers); //=> [ 2, 3 ]const numbers = [1, 2, 3];
console.log(numbers.reverse()); //=> [ 3, 2, 1 ]
console.log(numbers); //=> [ 3, 2, 1 ]const numbers = [1, 2, 3];
console.log(numbers.reverse()); //=> [ 3, 2, 1 ]
console.log(numbers); //=> [ 3, 2, 1 ]const numbers = [3, 1, 2];
console.log(numbers.sort()); //=> [ 1, 2, 3 ]
console.log(numbers); //=> [ 1, 2, 3 ]const numbers = [3, 1, 2];
console.log(numbers.sort()); //=> [ 1, 2, 3 ]
console.log(numbers); //=> [ 1, 2, 3 ]const numbers = [1, 2, 3];
console.log(numbers.splice(1, 2)); //=> [ 2, 3 ]
console.log(numbers); //=> [1]const numbers = [1, 2, 3];
console.log(numbers.splice(1, 2)); //=> [ 2, 3 ]
console.log(numbers); //=> [1]Accessor: includes(), join(), slice()
console.log([1, 2, 3].includes(1)); //=> trueconsole.log([1, 2, 3].includes(1)); //=> trueconsole.log([1, 2, 3].join(' ')); //=> "1 2 3"console.log([1, 2, 3].join(' ')); //=> "1 2 3"console.log([1, 2, 3].slice(1, 2)); //=> 2console.log([1, 2, 3].slice(1, 2)); //=> 2Iteration: map(), filter(), reduce(), every(), some()
const array = [1, 2, 3, 4, 5, 6];
console.log(array.map((value) => value * 2)); //=> [ 2, 4, 6, 8, 10, 12 ]const array = [1, 2, 3, 4, 5, 6];
console.log(array.map((value) => value * 2)); //=> [ 2, 4, 6, 8, 10, 12 ]const array = [1, 2, 3, 4, 5, 6];
console.log(array.filter((value) => value % 2 !== 0)); //=> [ 1, 3, 5 ]const array = [1, 2, 3, 4, 5, 6];
console.log(array.filter((value) => value % 2 !== 0)); //=> [ 1, 3, 5 ]const array = [1, 2, 3, 4, 5, 6];
console.log(array.reduce((addition, value) => addition + value, 0)); //=> 21const array = [1, 2, 3, 4, 5, 6];
console.log(array.reduce((addition, value) => addition + value, 0)); //=> 21const array = [2, 4, 6];
console.log(array.every((value) => value % 2 == 0)); //=> trueconst array = [2, 4, 6];
console.log(array.every((value) => value % 2 == 0)); //=> trueconst array = [1, 2, 3, 4, 5, 6];
console.log(array.some((value) => value % 2 == 0)); //=> trueconst array = [1, 2, 3, 4, 5, 6];
console.log(array.some((value) => value % 2 == 0)); //=> true