/js/ Recent content in Js on Tianyi as a Developer Hugo -- gohugo.io en-us Tue, 07 Apr 2020 00:00:00 +0000 /js/javascript-async/ Tue, 07 Apr 2020 00:00:00 +0000 /js/javascript-async/ Error propagatioon It is not necessary to async function foo() { let rand = ~~(Math.random() * 10); if (rand % 2) { return "Hello"; } else throw Error("Error at foo!"); } async function bar() { let x = await foo(); x += " world"; return x; } async function baz() { let y = await bar(); y += "!!!"; return y; } let a = 0; (async () => { for (let i = 0; i < 10; i++) { try { res = await baz(); console. /js/js-ndarray/ Mon, 23 Mar 2020 00:00:00 +0000 /js/js-ndarray/ Initialising multidimensional arrays in Javascript can be tricky because some initialisation approches lead to unexpected behaviour due to shallow copying. 2D Arrays (Matrices) If we try to create a 4 \(\times\) 4 matrix by filling an empty array with 4 zero-filled arrays each with 4 zeros using the Array(n).fill(e) syntax: let arr = Array(4).fill(Array(4).fill(0)); console.table(arr); ┌─────────┬───┬───┬───┬───┐ │ (index) │ 0 │ 1 │ 2 │ 3 │ ├─────────┼───┼───┼───┼───┤ │ 0 │ 0 │ 0 │ 0 │ 0 │ │ 1 │ 0 │ 0 │ 0 │ 0 │ │ 2 │ 0 │ 0 │ 0 │ 0 │ │ 3 │ 0 │ 0 │ 0 │ 0 │ └─────────┴───┴───┴───┴───┘ and then try to change the element \(arr_{1,2}\):