为收音机分配值，使用PHP选择或复选框输入

Question

I've got a registration form. When users submit the form after entering an invalid coupon code, the page reloads and I show the form again with all the data they entered. It's easy with input fields but I can't think of a simple way to do the same with radio, checkboxes and selects.

For example I have :

<input type="radio" name="gender" value="male" />
<input type="radio" name="gender" value="female" />

I have my PHP variable $gender that contains 'male'. But how to have the radio with 'male' selected?

Same question with my selects and checkboxes.

Answer 1

For a small number of options you could use a ternary operator like this.

<input type="radio" name="gender" value="male" <?php echo ($gender == 'male') : 'selected="selected"' : '';?> />
<input type="radio" name="gender" value="female" <?php echo ($gender == 'female') : 'selected="selected"' : '';?> />

Not the most subtle way but it will work. For more complicated situations its advisable to use a DOM parser like DOMDocument etc.