let命令let 用于声明变量,类似于var, 声明的变量只在代码块中有效{ let a=66; var b=88;}alert(a) //a is not definedalert(b) //88let 不能重复声明——不允许在相同作用域内重复声明同一个变量function(){ let a=1; let a=2;}//
While Mike was walking in the subway, all the stuff in his back-bag dropped on the ground. There were several fax messages among them. He concatenated these strings in some order and now he has string