JavaScript Hoisting

时间 2019-11-06

标签 javascript hoisting 栏目 JavaScript 繁體版

原文原文链接

Hoisting is JavaScript's default behavior of moving all declarations to the top of the current scope (to the top of the current script or the current function).javascript

function number() {
    return 1;
}

(function() {
    try {
        number();
    } catch (ex) {
        console.log(ex);
    }
    var number = function number() {
        return 2;
    };

    console.log(number());
})();

console.log(number());

js会把声明提高到当前做用域的最上边，包括变量和函数声明。java

function number() {
    return 1;
}

(function() {
    console.log(number());

    function number() {
        return 2;
    }
})();

console.log(number());