I have an input which when im clicking - i want to see alert with '1,2,3,4...' (each press)
<input type='button' value='press' onclick='Clicked();' />
<script>
var t
function Clicked()
{
t=func;
t();
}
function func()
{
var count=0;
return new function () // <=== new or not new ???
{
count++;
alert(count);
}
}
</script>
If im adding the 'new' in the return and click , it says : '1,1,1,1,...'
If 开发者_如何学编程im removing the 'new' it doesnt work...
My goal is to use this to get : '1,2,3,4...'
Can someone explain to me what happens ?
You need to use the returned function:
var t = func()
function Clicked() {
t();
}
function func() {
var count=0;
return function () {
count++;
alert(count);
}
}
Example
You have to put the count declaration out of the "func" function and into the global namespace. Like this:
var count=0;
function func() {
count++;
alert(count);
}
You're creating a new var count every time the clickevent fires.. You should place the var count = 0 outside the function as a global variable..
oh and btw, throw out the return stuff please this will work properly:
var count = 0;
function func()
{
count++;
alert(count);
}
And call this method like this: func();
You are getting 1,1,1,1
because you are redefining count every time you call func()
.
In your case you will need to either put the count variable in the global scope:
var t;
var count = 0;
or change the way you are doing things a little:
var t = 0;
function Clicked(){
t = func(t);
}
function func(count){
count++;
alert(count)
return count;
}
Personally I like the second one. You have less global variables, one less function declaration, and it is cleaner
var t
function Clicked()
{
t=func;
t();
}
var count=0;
function func()
{
return new function () // <=== new or not new ???
{
count++;
alert(count);
}
}
精彩评论