在JavaScript中创建可重用函数

Question

I'm extracting a part of the current button ID and want it to re-use this in several other functions.

How could I make the following section common,

var idRec = $(this).attr("id"),
inp = idRec.substr(4,this.id.length);

So that it could be used in multiple .on('click',) events. Please see the following code and advise,

$(function() {
  function studentsRecords(e) {
      //do_somehting
}

$(document).on('click', '.studentID', function(e) {
    var idRec = $(this).attr("id"),
    inp = idRec.substr(2, this.id.length);
    //do_something_using_inp
  }).on('click', '.admissionID', function(e) {
    //do_something_else_using_inp
  });
});

Answer 1

$(function() {
    function studentsRecords(e) {
        //do_somehting
    }

    function get_id(that){
      var idRec = that.id;
      var inp = idRec.substr(2,that.id.length);
      return inp
    } 


    $(document)
        .on('click', '.studentID', function(e) {

             var inp = get_id(this);
            //do_something_using_inp
        })
        .on('click', '.admissionID', function(e) {
             var inp = get_id(this);
            //do_something_else_using_inp
        })
})

Answer 2

You can declare inp before click function . http://fiddle.jshell.net/x3xo25vz/