check a checbox javascript code example

Example 1: javascript check uncheck checkbox

document.getElementById("myCheckBoxID").checked = true; // Check
document.getElementById("myCheckBoxID").checked = false;// Uncheck

Example 2: checked unchecked through js

document.getElementById("checkbox_id").checked;
//If checked returns true;
//else returns false;

Example 3: html checkbox status

app.innerHTML = '<h1>Hello, world!</h1>';