jquery find与id属性

const body = () => $('body').find('#elemID');
const id = () => $('#elemID');

const idJs = () => document.getElementById('elemID');

function performanceCalc(fn, params) {
    const start = new Date()
    const result = fn()
    const end = new Date()

    console.log(`Result: ${result} ${params}. Execution Time: ${end - start} ms`)
}

performanceCalc(body, 'body')

performanceCalc(id, 'id')

performanceCalc(idJs, 'idJs')

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<div id="elemID"></div>