In Javascript scripts, the parameter reference principle is that the referenced parameter can be modified internally (such as attribute), but the reference corresponding to the parameter cannot be modified.
A test example is as follows:
Copy codeThe Code is as follows:
<Script language = "javascript">
// Dosomething1. for reference, the variable itself cannot be modified, but the internal structure of the variable can be modified.
Function dosomething1 (){
A = 'try ';
}
// Test 1
Function test1 (){
Var a = {a: 'test', B: 'Is ', c:' OK '};
Dosomething1 ();
Alert (a. );
}
// Dosomething2
Function dosomething2 (v ){
V. a = v. a + '!!! '; // Modify the attributes of the referenced variable. The modification is successful.
V = 'try'; // An error occurred while trying to modify the variable reference.
}
// Test 2
Function test2 (){
Var a = {a: 'test', B: 'Is ', c:' OK '};
Dosomething2 ();
Alert (a. );
}
Test2 ();
</Script>