In JavaScript, you can overwrite or modify built-in properties and methods of objects, including those of the Array prototype. However, it is generally not recommended to modify the behavior of built-in objects because it can lead to unexpected consequences and compatibility issues with other code. That being said, if you still need to override a built-in property or method, you can achieve it by modifying the object's prototype. Here's an example of how you can override the push() method of the Array prototype:

Array.prototype.push=function() {
 var arr=[1,2,3];
 arr.push(4);//it will console the array with values i.e [1,2,3] as push function has been overridden