Here we are learning JavaScript programming language (JS), you can use any programming language that you are good at, the point here is that we only learn logic.

let string = "";
for (let i = 1; i < 10; i++) {
for (let j = 1; j <= 10; j++) {
string +="* ";
}
string += "< br >"
}
document.getElementById("sesuai nama div").innerHTML = string;

let string = "";
for (let i = 1; i <= 10; i++) {
for (let j = 1; j <= i; j++) {
string +="* ";
}
string += "< br >";
}
document.getElementById("sesuai nama div").innerHTML = string;

let string = "";
for (let i = 10; i >= 1; i--) {
for (let j = 1; j <= i; j++) {
string +="* ";
}
string += "< br >";
}
document.getElementById("sesuai nama div").innerHTML = string;

let string = "";
for (let i = 10; i >= 1; i--) {
for (let j = 1; j <= i; j++) {
string +="* ";
}
string += "< br >";
}
for (let k = 9; k >= 1; k--) {
for (let u = 1; u <= k; u++) {
string += "* ";
}
string += "< br >";
}
document.getElementById("sesuai nama div").innerHTML = string;

Thus our practice today, I hope it can be understood. The above method is not the only way to create a pattern. There are many more ways that are shorter than this. Keep practicing, and don't give up