Can I access the function arguments outside the function?
Here is my code:
function viewmessage(username,name) {
//alert(name + " : " + username);
$('#heading').html(name);
$.get('/notification/viewmessage', {user:username}, function(data) {
$('#messagesfrom').html(data);
$('#newmessage').slideDown(200);
});
}
alert(name + " : " + username);
You can use RegEx (regular expressions) to get the arguments:
function viewmessage(username, name) {/*...*/}
var args = viewmessage.toSource()
.match(/\((?:.+(?=\s*\))|)/)[0]
.slice(1).split(/\s*,\s*/g);
//args = ["username", "name"]
Make sure though, you don't have any spaces after the ( or before the ). Otherwise, you might have this result:
function viewmessage( username, name ) {/*...*/}
var args = viewmessage.toSource()
.match(/\((?:.+(?=\s*\))|)/)[0]
.slice(1).split(/\s*,\s*/g);
//args = [" username", "name "]
Or you use trim() on each of the arguments after you gathered them:
args.forEach(function (e, i, a) {a[i] = e.trim();});
//args = ["username", "name"]
You can't, unless you declare the variable outside the function.
You can only use the same variable names in the global scope:
function viewmessage(username, name){
window.username = username;
window.name = name;
}
alert(window.name + " : " + window.username ); // "undefined : undefined"
alert(name+" : "+username); // ReferenceError: 'name' not defined
In a local scope, you have to use variable names which are re-declared inside the function:
var username2, name2;
function viewmessage(username, name){
username2 = username; // No "var"!!
name2 = name;
}
alert(username2 + " : " + name2); // "undefined : undefined"
viewmessage('test', 'test2');
alert(username2 + " : " + name2); // "test : test2"
You can return those variables in the function:
var viewmessage = function(username, name){
// Blabla
return {
username: username,
name: name
}
}
// And then...
var vm = viewmessage('wutup', 'Peter');
alert(vm.name +" : "+ vm.username);
Inside the function me put an the username as id for a submit button. or can use an empty div too.
function viewmessage(username,name){
//alert(name+" : "+username);
$("#submit").attr('id', username);
$('#heading').html(name);
touser = username;
$.get('/notification/viewmessage',{user:username},function(data){
$('#messagesfrom').html(data);
$('#newmessage').slideDown(200);
});
}
var touser = $("#submit").attr("id");
alert(touser);
thanks to those who answered my question.
You don't access the function's parameters from outside the function. That is what variable scoping is all about.
If what you want is to access the variable's value, you need to pass that value to a global variable from inside your function, and then you'll be able to access that value from outside.
Do not confuse the variable with the value.
This relates to the scoping of arguments and where they are defined. You need to wrap the alert in a function that receives the arguments. Either a function that calls viewMessage and then alert, or if you want the alert after the ajax request move the alert into the success handler, as shown:
function viewmessage(username,name){
$('#heading').html(name);
$.get('/notification/viewmessage',{user:username},function(data){
$('#messagesfrom').html(data);
$('#newmessage').slideDown(200);
alert(name+" : "+username);
});
}
