javascript函数中变量的范围
javascript函数中变量的范围Java代码
var first = 'hi there';
var first = (function() {
console.log("first", first); // undefined
var first = "hello world";
})();
//相当于
var first = 'hi there';
var first = (function() {
var first;//the variable declaration moved to the top
console.log("first", first); // undefined
var first = "hello world";
})();
// second test case
var second = 'hi there';
var second = (function() {
console.log("second", second ); // "hi there"
// here, we DO NOT declare a local "second" variable
})();
// in the second test case, we don't declare the local variable, so the console.log call refers to the global variable and the value is not "undefined"
//link:http://jsfiddle.net/pomeh/ynqBs/ 谢谢分享希望于楼主多多交流
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