Number Pattern in JavaScript

In this post, you will learn how to print various number pattern programs using the JavaScript programming. Such a type of logical question is generally asked in an interview or in competitive exams. This can be helpful to improve your logical programming skills and is helpful in game development and other logical application development.

A pattern program consists of patterns of numbers, letters, and symbols in a particular form. In the programming language, the loop condition is considered important for printing patterns. Generally, nested loops are used in a number of patterns and shapes in printing programs.

JavaScript Number Pattern Program 1

In the following JavaScript program, we used nested for loops to print a number pattern in the shape of a triangle.

let rows = 6; 
let char = "";

// External loop
for (let i = 1; i <= rows; i++) {
  // Internal loop
  for (let j = 1; j <= i; j++) {
    char += j;
  }
  char += "\n";
}
console.log(char);

Output of the above code:

1
12
123
1234
12345
123456

JavaScript Number Pattern Program 2

let rows = 6; 
let char = "";

// External loop
for (let i = 1; i <= rows; i++) {
  // Internal loop
  for (let j = 1; j <= i; j++) {
    char += i;
  }
  char += "\n";
}
console.log(char);

Output of the above code:

1
22
333
4444
55555
666666

JavaScript Number Pattern Program 3

let rows = 6; 
let char = "";

let count = 1;

// External loop
for (let i = 1; i <= rows; i++) {
  // Internal loop
  for (let j = 1; j <= i; j++) {
    char += count;
    count++;
  }
  char += "\n";
}
console.log(char);

Output of the above code:

1
23
456
78910
1112131415
161718192021

JavaScript Reverse Triangle Program 4

let rows = 6; 
let char = "";

let count = 1;

// External loop
for (let i = 1; i <= rows; i++) {
  for (let j = 1; j <= rows - i + 1; j++) {
    char += j;
  }
  char += "\n";
}
console.log(char);

Output of the above code:

123456
12345
1234
123
12
1

JavaScript Number Pyramid Pattern 5

let rows = 6; 
let char = "";

// External loop
for (let i = 1; i <= rows; i++) {
  // creating spaces
  for (let j = 1; j <= rows - i; j++) {
    char += " ";
  }
  // creating numbers
  for (let k = 1; k <= 2 * i - 1; k++) {
    char += k;
  }
  char += "\n";
}
console.log(char);

Output of the above code:

     1
    123
   12345
  1234567
 123456789
1234567891011

JavaScript Reverse Pyramid Pattern 6

let rows = 6; 
let char = "";

// External loop
for (let i = 1; i <= rows; i++) {
  // creating spaces
  for (let j = 1; j < i; j++) {
    char += " ";
  }
  // creating numbers
  for (let k = 1; k <= 2 * (rows - i + 1) - 1; k++) {
    char += k;
  }
  char += "\n";
}
console.log(char);

Output of the above code:

1234567891011
 123456789
  1234567
   12345
    123
     1

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