how to add placeholder for select box code example
Example 1: placeholder select html
<!DOCTYPE html>
<head>
</head>
<body>
<select name="food">
<option value="" disabled selected hidden>select food</option>
<option value="apple">apple</option>
<option value="melon">melon</option>
</select>
</body>
Example 2: html select placeholder
//<select> tag doesn't have any placeholder attribute.
//But you can make a placeholder by making
//your first option disabled and selected.
//Maybe you would want that option to be hidden,
//just add hidden
//in Angular you need to add value="undefined"
<select name="gender" required>
<option value="" selected disabled hidden>Select a Gender</option>
<option value="Female">Female</option>
<option value="Male">Male</option>
<option value="Intersex">Intersex</option>
<option value="Trans">Trans</option>
<option value="Non-Conforming">Non-Conforming</option>
<option value="Personal">Personal</option>
<option value="Eunuch">Eunuch</option>
</select>