jQuery到Javascript等效项

Question

I'm new to JavaScript and also jQuery and have been trying to convert this script:

$(document).ready(function () {
    $('#var').val('value');
    document.forms[0].submit();
});

to use only JavaScript, can anyone explain the equivalent functions in js?

Answer 1

Use DOMContentLoaded for equivalent of ready .

The DOMContentLoaded event is fired when the initial HTML document has been completely loaded and parsed, without waiting for stylesheets, images, and subframes to finish loading. A very different event - load - should be used only to detect a fully-loaded page. It is an incredibly popular mistake for people to use load where DOMContentLoaded would be much more appropriate, so be cautious.

Use getElementById for id selector.

Returns a reference to the element by its ID.

Javascript Code:

document.addEventListener("DOMContentLoaded", function (event) { // Equivalent of ready
    document.getElementById('var').value = 'value';
    document.forms[0].submit();
});