Question

i was searching google just to have way out to generate & submit form by jquery and i found code snippet but few things was not clear to me.

function submitValues(url, params) {
var form = [ '<form method="POST" action="', url, '">' ];

for(var key in params) 
    form.push('<input type="hidden" name="', key, '" value="', params[key], '"/>');

form.push('</form>');

jQuery(form.join('')).appendTo('body')[0].submit();
}

why [] this third bracket is used like

var form = [ '<form method="POST" action="', url, '">' ];

what is the meaning of the line jQuery(form.join(”)).appendTo(‘body’)[0].submit();
why form.join(”) has been used and why write like appendTo(‘body’)[0] why [0]

please guide me in detail for those above bold syntax. thanks

Answer 1

By questions order:

1. Brackets [] define an array. So in the second line it defines array with three items:

   var form = [ "first item", "second item", "third item", ... etc ];
   

2. form.join('') joins all the elements of form array with delimiter of empty string, so form becomes a string with concatenated substrings from the array.

3. jQuery(form.join('')) converts your string into DOM elements and appendTo("body") appends these elements (<form><input> ... </form>) inside body.

4. Using [0] you get your form, however not as a jQuery object but as DOM element. Native form element has method submit which is called with .submit().

For any doubts with native JavaScript methods and functions you can read MDN. jQuery documentation is provided at api.jquery.com.