This will give you the distance between 2 or 3 (depends how many axis you have) points on a cartesian plane

cartesianPointDist.js

// This will give you the distance between 2 or 3 (depends how many axis you have) points on a cartesian plane
// © Arthur Guiot 2017


// Sqare Root algorithm based on babylonian method
// @param n - the number to compute the square root of
// @param g - the best guess so far (can omit from initial call)
const squareroot = (n, g) => {
    if (!g) {
        // Take an initial guess at the square root
        g = n / 2.0;
    }
    const d = n / g;              // Divide our guess into the number
    const ng = (d + g) / 2.0;     // Use average of g and d as our new guess
    if (g == ng) {          
        // The new guess is the same as the old guess; further guesses
        // can get no more accurate so we return this guess
        return g;
    }
    // Recursively solve for closer and closer approximations of the square root
    return squareroot(n, ng);
};
// The actual function
Math.dist = (x1, y1, x2, y2, z1, z2) => { 
  if(!x2) x2=0; 
  if(!y2) y2=0;
  if(!z1) z1=0; 
  if(!z2) z2=0;
  return squareroot((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1)+(z2-z1)*(z2-z1)); 
}

test.js

Math.dist(0,0,1,1,0,0);
// 1.41421356237
Math.dist(0,0,1,1);
// 1.41421356237
// Try it out!