Introduction to citation examples in Javascript_Basic knowledge

In Javascript scripts, the reference principle of parameters: the internal parts of the referenced parameters (such as attributes) can be modified, but the reference corresponding to the parameter cannot be modified.

A test example is as follows:

Copy code The code is as follows:

< ;script language="javascript">
//dosomething1, for references, the variable itself cannot be modified, but the internal structure of the variable can be modified
function dosomething1(a){
a = 'try';
}

//Test 1
function test1(){
var a = {a:'test',b:'is',c:'ok'};
dosomething1(a);
alert(a.a);
}
//dosomething2
function dosomething2(v){
v.a = v.a '!!!'; //Modify the reference variable Attribute, modified successfully
v = 'try'; //Trying to modify variable reference, modification failed
}
//Test 2
function test2(a){
var a = {a :'test',b:'is',c:'ok'};
dosomething2(a);
alert(a.a);
}
test2();
< /script>