TypeScript: Errors

error TS2339: Property 'style' does not exist on type 'Element'.

error TS2339: Property 'style' does not exist on type 'Element'.

const x = document.querySelector("span.x42663").style;

change the above to

const x = (document.querySelector("span.x42663") as HTMLElement).style;

// or

const x = (<HTMLElement> document.querySelector("span.x42663")).style;

error TS2339: Property 'value' does not exist on type 'HTMLElement'

error TS2339: Property 'value' does not exist on type 'HTMLElement'.

solution.

change the line

document.getElementById("user_input_24066").value

to

(document.getElementById("user_input_24066") as HTMLInputElement).value

// or

(<HTMLInputElement> document.getElementById("user_input_24066")).value

TypeScript: Declare Library by Triple-Slash Directives

make TypeScript aware of libs.

/// <reference path="xah_keyboard_lib.ts" />

SVG Element Types

type of svg elements, such as circle, is SVGElement

type of svg container, such as svg, is SVGSVGElement

〔see SVG: Basic Examples〕

Declare Tuple

// declare a array as array of tuple, each element is a array of [string, number]
type source_text_96834 = { [key: string]: Array<[string, number]> }