JavaScript Hoisting

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會把聲明提高到當前做用域的最上邊,包括變量和函數聲明。java

function number() {
    return 1;
}

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

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

console.log(number());
相關文章
相關標籤/搜索