属性选择器 - JavaScript

HTML

<div class="test">
    <div class="a" data-t="a"></div>
    <div class="a" data-t="1"></div>
</div>

JavaScript

var a = document.querySelector( '[data-t=a]' );
try {
    var b = document.querySelector( '[data-t=1]' );
}
catch(e) {
    alert( '[data-t=1]' );
}
var a1 = document.querySelector( '[data-t="a"]' );
var b1 = document.querySelector( '[data-t="1"]' );

console.log( a, a1, b );