# JavaScript: Check whether a point lies strictly inside a given circle

## JavaScript Basic: Exercise-120 with Solution

Write a JavaScript program to check if a point lies strictly inside the circle.

Input:

Center of the circle (x, y)

Radius of circle: r

Point inside a circle (a, b)

**Sample Solution: **

**JavaScript Code:**

```
// Function to check if a point (a, b) is inside a circle with center (x, y) and radius r
function check_a_point(a, b, x, y, r) {
// Calculate the squared distance between the center of the circle (x, y) and the point (a, b)
var dist_points = (a - x) * (a - x) + (b - y) * (b - y);
// Square the radius for comparison
r *= r;
// Check if the squared distance between points is less than the squared radius
if (dist_points < r) {
return true; // Point is inside the circle
}
return false; // Point is outside the circle or on the circle
}
// Test cases
console.log(check_a_point(0, 0, 2, 4, 6)); // Output: true (Point (0,0) is inside the circle with center (2,4) and radius 6)
console.log(check_a_point(0, 0, 6, 8, 6)); // Output: false (Point (0,0) is outside the circle with center (6,8) and radius 6)
```

Output:

true false

**Live Demo: **

See the Pen javascript-basic-exercise-120 by w3resource (@w3resource) on CodePen.

**Flowchart: **

**ES6 Version:**

```
// Function to check if a point (a, b) is inside a circle with center (x, y) and radius r
const check_a_point = (a, b, x, y, r) => {
// Calculate the squared distance between the center of the circle (x, y) and the point (a, b)
const dist_points = (a - x) ** 2 + (b - y) ** 2;
// Square the radius for comparison
r **= 2;
// Check if the squared distance between points is less than the squared radius
if (dist_points < r) {
return true; // Point is inside the circle
}
return false; // Point is outside the circle or on the circle
}
// Test cases
console.log(check_a_point(0, 0, 2, 4, 6)); // Output: true (Point (0,0) is inside the circle with center (2,4) and radius 6)
console.log(check_a_point(0, 0, 6, 8, 6)); // Output: false (Point (0,0) is outside the circle with center (6,8) and radius 6)
```

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