JSFiddle - React, Tailwind, and code Playground

by tea4two

HTML

<form>    
ご氏名: <input type="text"><br>
EMAIL: <input type="email" id="email" value="[email protected]">
</form>

JavaScript

var emailField = document.getElementById('email');

//フォーカス(入力ができる状態)時
emailField.onfocus = function() {
    if( emailField.value == '[email protected]' ) {
        emailField.value = '';
    }
}

//フォーカスが外れた時
emailField.onblur = function() {
    if( emailField.value == '' ) {
        emailField.value = '[email protected]';
    }
}