js 细节笔记越大型的项目,越需要知道这些知识
var a = [1,2,3]; a.splice(1,1,2,3,4); console.log(a) //[1,2,3,4,3] [1,2,3].splice(1,1,2,3,4); //[2] 返回的被删除的元素 var foo = 1; function main() { alert(foo); var foo = 2; alert(this.foo); this.foo = 3; } window.foo; //1 main(); //undefined 1 new main(); //undefined undefined window.foo; //3 ...