Mark array() method as deprecated with warning message

src/math/p5.Vector.js

@@ -2934,9 +2934,13 @@ class Vector {
     return this.sub(surfaceNormalCopy.mult(2 * this.dot(surfaceNormalCopy)));
   }
 
+  _showArrayDeprecationWarning() {
+  }
+
   /**
    * Returns the vector's components as an array of numbers.
    *
+   * @deprecated
    * @return {Number[]} array with the vector's components.
    * @example
    * <div class = "norender">
@@ -2952,6 +2956,7 @@ class Vector {
    * </div>
    */
   array() {
+    this._showArrayDeprecationWarning();
     return [this.x || 0, this.y || 0, this.z || 0];
   }
 
@@ -3781,6 +3786,7 @@ class Vector {
    * method to copy into your own vector.
    */
   /**
+   * @deprecated
    * @static
    * @param  {p5.Vector} v the vector to convert to an array
    * @return {Number[]} an Array with the 3 values
@@ -3900,6 +3906,17 @@ function vector(p5, fn) {
    */
   p5.Vector = Vector;
 
+  let arrayDeprecationWarningShown = false;
+  Vector.prototype._showArrayDeprecationWarning = function() {
+    if (p5._friendlyError && !arrayDeprecationWarningShown) {
+      p5._friendlyError(
+        'array() is deprecated and will be removed in a future version of p5.js.',
+        'p5.Vector.array'
+      );
+      arrayDeprecationWarningShown = true;
+    }
+  };
+
   /**
    * The x component of the vector
    * @type {Number}