JSFiddle - React, Tailwind, and code Playground
JavaScript
var n=prompt("enter the size");
for(i=0;i < n ; i++){
for(j=0 ; j < n; j++){
document.write('<input type="checkbox" id="chk_'+i+j+'" onclick="func(this)" />');
}
document.write("<br />");
}
function func(that){
for(i=0;i < n ; i++){
for(j=0 ; j < n; j++){
if((that).checked == true){
document.getElementById('chk_'+i+j).checked=true
}
else{
document.getElementById('chk_'+i+j).checked=false
}
}
}
}