let n = 5; // row or column count
// defining an empty string
let string = "";
for(let i = 0; i < n; i++) { // external loop
for(let j = 0; j < n; j++) { // internal loop
if(i === 0 || i === n - 1) {
string += "*";
}
else {
if(j === 0 || j === n - 1) {
string += "*";
}
else {
string += " ";
}
}
}
// newline after each row
string += "
";
}
// printing the string
console.log(string);
/*
*****
* *
* *
* *
*****
*/