JSFiddle - React, Tailwind, and code Playground

by Liu David

HTML

<script src="https://cdn.bootcss.com/jquery/3.1.0/jquery.min.js"></script>
<button id="btnTest">
测试
</button>

<button id="btnTest2">
测试局部变量的生存期
</button>

JavaScript

function test(arr) {
    var myArr = arr.map(function (obj) {
        return 'great ' + obj;
    });
    $('#btnTest').on('click', function () {
        alert(myArr[1]);
    });

	//following change will change the alert
	//so js variable's scope is in function?
    //myArr = ['hello', 'js'];

}


var myArr = ['hello', 'world'];
test(myArr);

myArr = ['hello', 'js'];
myArr = null;



//+++++++++++++++++++
function test2(){
	var i=0;
	$('#btnTest2').on('click', function () {
		alert(i);
		i++;
	});
}


test2();