Question

I was wondering about the differences between Grep and Filter :

Filter :

Reduce the set of matched elements to those that match the selector or
pass the function’s test.

Grep :

Finds the elements of an array which satisfy a filter
function. The original array is not affected.

ok.

so if I do this in GREP :

var arr = [ 1, 9, 3, 8, 6, 1, 5, 9, 4, 7, 3, 8, 6, 9, 1 ];

myNewArray= jQuery.grep(arr, function(n, i){
  return (n != 5 && i > 4);
});

I could do also :

 var arr = [ 1, 9, 3, 8, 6, 1, 5, 9, 4, 7, 3, 8, 6, 9, 1 ];

myNewArray= $(arr).filter( function(n, i){
  return (n != 5 && i > 4);
});

In both situations I still can access to the original array…

so…where is the difference ?

Answer 1

They both function in similar ways however they differ in their usages.

The filter function is intended to be used with html elements, and that is why it is a chainable function that returns a jQuery object and it accepts filters like “:even”, “:odd” or “:visible” etc. You can’t do that with the grep function, which is intended to be a utility function for arrays.