My jquery code is divided file is divided over 2 files.
In one of the file, I define a function
function something(input){ //does something } calling this function only works when the caller line is in the same file. But I need to call it from both files.
If I switch the function to the second file, again I get the same issue. The code in the same file can read it, but not the code in the other file.
Place your functions outside of $(document).ready(function() { }); to give them global scope. Anything placed within it cannot be accessed from the outside.
You can then look into using a namespace to encapsulate your functions. This helps to avoid clutter of the global namespace.
You need to create a namespace object, which is shared between your files.
fileA.js
window.mynamespace = window.mynamespace || {}; mynamespace.something = function(input) { // do something }; fileB.js
window.mynamespace = window.mynamespace || {}; mynamespace.something(); 
$(document).ready(function() { });
$(document).ready(function() { }); and other namespaces will be globally available on the page.