In the previous article, we have seen Java Program to Find Line Passing Through 2 Points

In this article we will discuss about how to find line passing through origin or not using Java programming language.

## Java Program to Check if Line Passes Through the Origin

Before jumping into the program directly, let’s first know how can find line passing through origin or not

**Explanation****:**

Equation of a line passing through two points (a1, b1) and (a2, b2) is given by b-b1 = ((b2-b1) / (a2-a1))(a-a1) + z If line is also passing through origin, then z=0, so equation of line becomes b-b1 = ((b2-b1) / (a2-a1))(a-a1) Keeping a=0, b=0 in the above equation we get, a1(b2-b1) = b1(a2-a1) So above equation must be satisfied if any line passing through two coordinates (a1, b1) and (a2, b2) also passes through origin (0, 0).

### Method-1: Java Program to Check if Line Passes Through the Origin By Using Static Value

**Approach :**

- Initialize and declare 2 point .
- Find the Boolean value of
`x1.a * (x2.b - x1.b) == x1.b * (x2.a - x1.a)`

- If value is true, then line is passing through origin .
- If not, then line is not passing through origin .

**Program :**

class Main { // Driver method public static void main(String args[]) { //points are declared IntsPoint x1 = new IntsPoint(1,28); IntsPoint x2 = new IntsPoint(2,56); boolean a= x1.a * (x2.b - x1.b) == x1.b * (x2.a - x1.a); if(a==true) System.out.println("line is passing through origin "); else System.out.println("line is not passing through origin "); } static class IntsPoint { int a,b; public IntsPoint(int a, int b) { this.a = a; this.b = b; } } }

Output: line is passing through origin

### Method-2: Java Program to Check if Line Passes Through the Origin By User Input Value

**Approach :**

- Take input of values for 2 points.
- Find the Boolean value of
`x1.a * (x2.b - x1.b) == x1.b * (x2.a - x1.a)`

- If value is true, then line is passing through origin .
- If not, then line is not passing through origin .

**Program :**

import java.util.*; class Main { // Driver method public static void main(String args[]) { //Scanner class object created Scanner s = new Scanner(System.in); int l,m ; //taking input of point-1 values System.out.println("Enter values of point 1:"); l=s.nextInt(); m=s.nextInt(); //taking input of point-2 values IntsPoint x1 = new IntsPoint(l, m); System.out.println("Enter values of point 2 :"); l=s.nextInt(); m=s.nextInt(); IntsPoint x2 = new IntsPoint(l, m); boolean a= x1.a * (x2.b - x1.b) == x1.b * (x2.a - x1.a); if(a==true) System.out.println("line is passing through origin "); else System.out.println("line is not passing through origin "); } static class IntsPoint { int a,b; public IntsPoint(int a, int b) { this.a = a; this.b = b; } } }

Output: Enter values of point 1: 1 28 Enter values of point 2 : 2 56 line is passing through origin

Guys who are serious about learning the concepts of the java programming language should practice this list of programs in java and get a good grip on it for better results in exams or interviews.

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