SOURCE

var globalVariable1=0

//打印localVariablel
//document.write(localVariable1)
//打印globalVariable2
//document.write(glocalVariable2)

function test1(){
    var localVariablel=2;
    //打印globalVariablel
    document.write(globalVariable1)
    //打印localVariablel
    document.write(localVariablel)
}
test1()
//未定义时调用
document.write(globalVariable2)
var globalVariable2=1;

function test2(){
    var localVariablel2=3;
    //打印localVariablel
    //document.write(localVariablel)
}
test2()

//打印localVariablel2
//document.write(localVariablel2)
//打印globalVariablel
//document.write(globalVariablel)