I'm trying to find a shorter way to print a right-triangle and an isosceles triangle without using that many nested loops. Please help, here is my code so far, it works I just have trouble finding a shorter way to write it:
//right-triangle
let triangleStr = "";
let num = 5;
for (let i = 1; i <= num; i++) {
for (let j = 0; j < num - i; j++) {
triangleStr += " ";
}
for (let k = 0; k < i; k++) {
triangleStr += "*";
}
triangleStr += "\n";
}
console.log(triangleStr);
//isosceles-triangle
triangleString = "";
for (let i = 1; i <= num; i++) {
for (let j = 1; j <= num - i; j++) {
triangleString += " ";
}
for (let k = 1; k <= 2 * i - 1; k++) {
triangleString += "*";
}
triangleString += "\n";
}
console.log(triangleString);If you want to use only one loop, you can use repeat() method in ECMAScript6 or higher.
For Right triangle:
const line = 5;
let rightTriangle = "";
for (let l = 1; l <= line ; l++) {
const indent = line-l;
rightTriangle += `${" ".repeat(indent)}${"*".repeat(l)}${"\n"}`;
}
console.log(rightTriangle);For Isosceles triangle:
const line = 5;
let isoscelesTriangle = "";
for (let l = 1; l <= line ; l++) {
const indent = line - l;
isoscelesTriangle += `${" ".repeat(indent)}${"*".repeat(2*l-1)}${"\n"}`;
}
console.log(isoscelesTriangle);