CODEWITHSUNDEEP
javascriptnested-loops
PalesaDev
PalesaDev

Reputation: 67

Shorter Way of Prinitng Triangle Patterns JavaScript

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);

Upvotes: 1

Views: 459

Answers (1)

mahooresorkh
mahooresorkh

Reputation: 1444

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);

Upvotes: 1

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