JavaScript声明全局变量的两种方法

通过两端代码介绍JavaScript如何声明全局变量

在函数外定义全局变量

var oneVariable;
function setVariable(){
    oneVariable = "Variable set from within a function!";
}
function getVariable(){
    alert(oneVariable); // Outputs "Variable set from within a function!"
}

或者附加到window对象上

function setValue() {
    window.myValue = "test";
}
function getValue() {
    alert(window.myValue); // "test" (assuming setValue has run)
}