A. Simple Pattern

1.Print a horizontal line of stars.

// *****
const horizontalLine = function (n) {
    let str = ""
    for (let i = 1; i <= n; i++)
        str += "*";

    console.log(str);
}
horizontalLine(5)

2.Print a vertical line of stars.

/*
*
*
*
*
*
*/
const verticalLine = function (n) {
    let str = "";
    for (let i = 1; i <= n; i++) {
        str += "*\n";
    }
    console.log(str)
}

verticalLine(5)

B.Triangle Pattern :

1. Right Triangle Pattern & its inverted:

// *
// **
// ***
// ****

let rightTrianglePyramid = function (n) {
    let str = ""
    for (let i = 1; i <= n; i++) {
        for (let j = 1; j <= i; j++)
            str += "*";

        console.log(str);
        str = "";
    }
}

let rightTrianglePyramid_2 = function (n) {
    let str = "";
    for (let i = 1; i <= n; i++) {
        for (let j = 1; j <= i; j++)
            str = "*".repeat(i);

        console.log(str);
    }
}
rightTrianglePyramid(7);
rightTrianglePyramid_2(7);

// 1.2 Inverted Right Triangle Pyramid Pattern:
// ****
// ***
// **
// *
let invertedrightTrianglePyramid = function (n) {
    for (let i = 1; i <= n; i++) {
        let str = ""
        for (let j = n; j >= i; j--) {
            str += "*"
        }
        console.log(str);
        str = "";
    }
}
invertedrightTrianglePyramid(7)

2.Left Triangle Pattern & its inverted:

//    *
//   **
//  ***
// ****

let leftTrianglePyramid = function (n) {
    let str = "";
    for (let i = 1; i <= n; i++) {
        for (let j = 1; j < n - i + 1; j++)
            str += " ";

        for (let k = 1; k <= i; k++)
            str += "*";

        console.log(str);
        str = "";
    }
}
leftTrianglePyramid(7)

// 2.2 Inverted Left Triangle Pattern & its inverted:
// *****
//  ****
//   ***
//    **
//     *
let invertedLeftTrianglePyramid = function (n) {
    let str = "";
    for (let i = 1; i <= n; i++) {
        for (let j = 1; j <= i; j++)
            str += " ";

        for (let k = i; k <= n; k++)
            str += "*"

        console.log(str);
        str = "";
    }
}
invertedLeftTrianglePyramid(7);

C. Pyramid Pattern & its inverted :

//    *
//   ***
//  *****
// *******

let pyramid = function (n) {
    let str = ""
    for (let i = 1; i <= n; i++){
        for (let j = 1; j <= n - i; j++)
            str += " "

        for (let k = 1; k <= (2 * i - 1); k++)
            str += "*"

        console.log(str);
        str = "";
    }
}
pyramid(7)

// Inverted Pyramid Pattern:
// *******
//  *****
//   ***
//    *

let invertedPyramid = function (n) {
    let str = "";
    for (let i = 1; i <= n; i++){
        for (let j = 1; j < i; j++)
            str += " "

        for (let k = 1; k <= (2 * (n - i + 1) - 1); k++)
            str += "*"

        console.log(str);
        str = ""
    }
}
invertedPyramid(7)

D. Diamond Pattern :

/* Diamond Pattern:
   *
  ***
 *****
*******
 *****
  ***
   *
*/

let diamond = function (semiLength) {
    let n = semiLength;
    let str = ""
    for (let i = 1; i <= n; i++){
        for (let j = 1; j < (n - i + 1); j++)
            str += " "

        for (let k = 1; k <= (2 * i - 1); k++)
            str += "*"

        console.log(str);
        str = "";
    }

    // Lower part of pyramid
    for (let i = 1; i < n; i++){
        for (let j = 1; j <= i; j++)
            str += " "

        for (let k = 1; k <= (2 * (n - i) - 1); k++)
            str += "*"

        console.log(str);
        str = ""
    }
}

diamond(4);

E. Upcoming...

• Butterfly