Increasement number not rising in for loop

The problem is that the handlers you're assigning have an enduring reference to the i variable, not a copy of that variable as of when the function was created. They're closures over the i variable (and other things). More: Closures are not complicated

There are several ways to solve this.

1. You can put a piece of information on the elements so they can all share a single handler, which is probably preferred. (You actually already have that information in your example, we can figure out i from the elements' id values, but I'm assuming in the real world things are more complex.)

   $(document).ready(function() {
       for (var i = 0; i < 3; i++) {
           $("#test"+i).attr("data-index", i).click(clickHandler);
       }  
   
       function clickHandler() {
           alert("I am clicked! ("+this.getAttribute("data-index")+")");
           // Or:
           alert("I am clicked! ("+$(this).attr("data-index")+")");
       }
   });
   

   Note how we have just one handler function, and it handles clicks on all of the elements.

   Using a single handler may also mean you can take advantage of event delegation, hooking the click on an ancestor element rather than on each of these individual elements, e.g.:

   $("selector for ancestor").on("click", "[id^=test]", ...);
   

2. You can use a builder function to create the click handlers so that they close over something that doesn't change (an argument we pass to the builder):

   $(document).ready(function() {
       for (var i = 0; i < 3; i++) {
           $("#test"+i).on('click', buildHandler(i));
       }  
   
       function buildHandler(index) {
           return function() {
               alert("I am clicked! ("+index+")");
           };
       }
   });
   

Try something like this

$(document).ready(function() {
for (var i = 0; i < 3; i++) {
    $("#test"+i).on('click', function() {
       var value = $(this).attr('id');
           value=value.replace("test", "");
           value=parseInt(value)+1;
        alert("I am clicked! ("+value+")");
    });
}  
});