Analysis of two places where javascript scope is easily misremembered_javascript skills

1.

Copy code The code is as follows:

function fun()
{
var a="rxm";
b="cwr";
}
alert(a);//Error, a local variable
alert(b); //"cwr", bGlobal variables.

2.

Copy code The code is as follows:

var a="rxm";
function fun()
{
alert(a);
var a="123";
alert(a);
}
fun();
alert(a);

Output result: undefined;123;rxm