Question

how to set all links in iframe to “google.com” by javascript or jQuery ?

Answer 1

You can use the iframe’s contentWindow attribute to get a hold on the global object running in the iframe. From there you can do what you want.

$(iframe.contentWindow).find("a").each(function(){
  //replace url
})

But if url of the iframe is on another domain, this will trigger a XSS (cross server scripting) error and you won’t be able to access the window dom. This is a security feature, so it cannot be circumvented. In other words, you cannot to that.