En esta aplicación web dinámica, cómo cambiar el texto de Colorear el elemento del encabezado a Decolorar el elemento del encabezado haciendo clic en la casilla de verificación y también implementar ese texto en código Javascript con el método de alternancia .
La salida esperada es:

Aquí está el código que probé:
let myContainer = document.getElementById("myContainer"); function onTextAndColorChange(checkboxInput, labelId, headingId) { let checkboxElement = document.getElementById("checkboxInput"); console.log(checkboxElement.checked); let labelElement = document.getElementById("labelId"); /* I think the toggle method was implement here */ let headingElement = document.getElementById("headingId"); headingElement.classList.toggle("checked"); } let inputElement = document.createElement("input"); inputElement.type = "checkbox"; inputElement.id = "checkboxInput"; inputElement.onclick = function() { onTextAndColorChange(checkboxInput, labelId, headingId); }; myContainer.appendChild(inputElement); let labelElement = document.createElement("label"); labelElement.setAttribute("for", "checkboxInput"); labelElement.textContent = "Color the heading element"; labelElement.id = "labelId"; myContainer.appendChild(labelElement); let headingElement = document.createElement("h1"); headingElement.textContent = "heading Element"; headingElement.classList.add("heading"); headingElement.id = "headingId"; myContainer.appendChild(headingElement); @import url("https://fonts.googleapis.com/css2?family=Bree+Serif&family=Caveat:wght@400;700&family=Lobster&family=Monoton&family=Open+Sans:ital,wght@0,400;0,700;1,400;1,700&family=Playfair+Display+SC:ital,wght@0,400;0,700;1,700&family=Playfair+Display:ital,wght@0,400;0,700;1,700&family=Roboto:ital,wght@0,400;0,700;1,400;1,700&family=Source+Sans+Pro:ital,wght@0,400;0,700;1,700&family=Work+Sans:ital,wght@0,400;0,700;1,700&display=swap"); .checked { color: #7a0ecc; background-color: #f2ebfe; } <!DOCTYPE html> <html> <head></head> <body> <div id="myContainer"></div> </body> </html>Use la propiedad textContent para cambiar el texto de la etiqueta en la función:
labelElement.textContent = checkboxElement.checked ? "Uncolor the heading element" : "Color the heading element"; let myContainer = document.getElementById("myContainer"); function onTextAndColorChange(checkboxInput, labelId, headingId) { let checkboxElement = document.getElementById("checkboxInput"); console.log(checkboxElement.checked); let labelElement = document.getElementById("labelId"); labelElement.textContent = checkboxElement.checked ? "Uncolor the heading element" : "Color the heading element"; let headingElement = document.getElementById("headingId"); headingElement.classList.toggle("checked"); } let inputElement = document.createElement("input"); inputElement.type = "checkbox"; inputElement.id = "checkboxInput"; inputElement.onclick = function() { onTextAndColorChange(checkboxInput, labelId, headingId); }; myContainer.appendChild(inputElement); let labelElement = document.createElement("label"); labelElement.setAttribute("for", "checkboxInput"); labelElement.textContent = "Color the heading element"; labelElement.id = "labelId"; myContainer.appendChild(labelElement); let headingElement = document.createElement("h1"); headingElement.textContent = "heading Element"; headingElement.classList.add("heading"); headingElement.id = "headingId"; myContainer.appendChild(headingElement); @import url("https://fonts.googleapis.com/css2?family=Bree+Serif&family=Caveat:wght@400;700&family=Lobster&family=Monoton&family=Open+Sans:ital,wght@0,400;0,700;1,400;1,700&family=Playfair+Display+SC:ital,wght@0,400;0,700;1,700&family=Playfair+Display:ital,wght@0,400;0,700;1,700&family=Roboto:ital,wght@0,400;0,700;1,400;1,700&family=Source+Sans+Pro:ital,wght@0,400;0,700;1,700&family=Work+Sans:ital,wght@0,400;0,700;1,700&display=swap"); .checked { color: #7a0ecc; background-color: #f2ebfe; } <!DOCTYPE html> <html> <head></head> <body> <div id="myContainer"></div> </body> </html>