JSFiddle - React, Tailwind, and code Playground

HTML

<select id="selectionType">
    <option value="-1">Select One</option>
    <option value="0">Name</option>
    <option value="1">ID</option>
</select>
<input type="text" id="inputBox">

JavaScript

var placeholderText = {0:"Enter your name",1:"Enter your ID"};

$("#selectionType").on("change",function() {
    var selection = document.getElementById("selectionType");
    var inputBox = document.getElementById("inputBox");
    
    var selectedVal = selection.options[selection.selectedIndex].value;
    if (placeholderText[selectedVal] !== undefined) {
        inputBox.placeholder = placeholderText[selectedVal];
    }
});