NOTE: answer is dependent upon jQuery 1.6.1+
$('#selectBox :nth-child(4)').prop('selected', true); // To select via index
$('#selectBox option:eq(3)').prop('selected', true); // To select via value
Thanks for the comment, .get
won't work since it returns a DOM element, not a jQuery one. Keep in mind the .eq
function can be used outside of the selector as well if you prefer.
$('#selectBox option').eq(3).prop('selected', true);
You can also be more terse/readable if you want to use the value, instead of relying on selecting a specific index:
$("#selectBox").val("3");
Note: .val(3)
works as well for this example, but non-numeric values must be strings, so I chose a string for consistency.
(e.g. <option value="hello">Number3</option>
requires you to use .val("hello")
)