Answers for "value of checked checkbox"

html checkbox default checked

<!-- Add checked tag  -->
<input type="checkbox" name="vehicle3" value="Boat" checked>

javascript set checkbox checked based on value

//HTML
<input type="checkbox" id="Numbers">Short Numbers</input>
<button type="button" onClick="changeCheckbox()">Save</button>
//JAVASCRIPT
function changeCheckbox(){
  	if(value)
	document.getElementById("Numbers").checked = true;
}

how to make checkbox checked in html

<input type="checkbox" checked={props.completed} /> 

#for props completed is true/false , hence if completed is false then checkbox will not be clicked .
# if the checkbox is true it will be will be checked