标签：mozilla VID rem algorithm UNC dia bsp cts ocs
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/slice
The slice() method returns a shallow copy of a portion of an array into a new array object selected from begin to end (end not included). The original array will not be modified.
var animals = [‘ant‘, ‘bison‘, ‘camel‘, ‘duck‘, ‘elephant‘]; console.log(animals.slice(2)); // expected output: Array ["camel", "duck", "elephant"] console.log(animals.slice(2, 4)); // expected output: Array ["camel", "duck"] console.log(animals.slice(1, 5)); // expected output: Array ["bison", "camel", "duck", "elephant"]
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map
The map() method creates a new array with the results of calling a provided function on every element in the calling array.
var array1 = [1, 4, 9, 16]; // pass a function to map const map1 = array1.map(x => x * 2); console.log(map1); // expected output: Array [2, 8, 18, 32]
https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce
The reduce() method executes a reducer function (that you provide) on each member of the array resulting in a single output value.
const array1 = [1, 2, 3, 4]; const reducer = (accumulator, currentValue) => accumulator + currentValue; // 1 + 2 + 3 + 4 console.log(array1.reduce(reducer)); // expected output: 10 // 5 + 1 + 2 + 3 + 4 console.log(array1.reduce(reducer, 5)); // expected output: 15
The reducer function takes four arguments:
Your reducer function‘s returned value is assigned to the accumulator, whose value is remembered across each iteration throughout the array and ultimately becomes the final, single resulting value.
https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/reverse
The reverse() method reverses an array in place. The first array element becomes the last, and the last array element becomes the first.
var array1 = [‘one‘, ‘two‘, ‘three‘]; console.log(‘array1: ‘, array1); // expected output: Array [‘one‘, ‘two‘, ‘three‘] var reversed = array1.reverse(); console.log(‘reversed: ‘, reversed); // expected output: Array [‘three‘, ‘two‘, ‘one‘] /* Careful: reverse is destructive. It also changes the original array */ console.log(‘array1: ‘, array1); // expected output: Array [‘three‘, ‘two‘, ‘one‘]
标签：mozilla VID rem algorithm UNC dia bsp cts ocs
原文地址：https://www.cnblogs.com/chucklu/p/10262292.html
