How to automatically change values of combobox value based on input value in text box using php and html

问题

Please how can I populate combo box based on input value from textbox using HTML/PHP

E.g. *if textbox value equals "a" then combo box value equals (a,b,c,d) else if textbox value equals "b" then combo box value equals (e,f,g,h)

any help is highly welcome

回答1:

this script will do it.

    $("#TextInputID").change(function(){

    var optionsForA = ['a','b','c','d'];
    var optionsForB = ['e','f','g','h'];
    var options = '';

    var inputVal = $("#TextInputID").val();
    switch(inputVal) {
        case "a":
            for (var i=0;i<optionsForA.length;i++){
            options += '<option value="'+ optionsForA[i] + '">' + optionsForA[i] + '</option>';
            }
            break;
        case "b":
            for (var i=0;i<optionsForB.length;i++){
            options += '<option value="'+ optionsForB[i] + '">' + optionsForB[i] + '</option>';
            }
            break;
    }

    $('#comboboxid').find('option').remove().end().append(options);
});

回答2:

It's fairly simple and easy. There are two ways of doing it

1. Either do it on client side using javascript/jQuery by putting an onchange listener on the textbox each time it's value is changed check if it's a then place specific options in combobox, if it's b put other concerned options in combobox and so on ...

2. You can do it using PHP and AJAX as well, if textbox has a value like 'a' so truncate comboxbox options and using ajax fetch certain options from the database and append them to the comboxbox.

Need more explanation? hit me back :)

来源：https://stackoverflow.com/questions/36972669/how-to-automatically-change-values-of-combobox-value-based-on-input-value-in-tex