Astonished to find out that a line like this :
$('#TextBox').val(parseInt($('#TextBox').val())++ );
Will not work !
I've done some tests, it plays out to the conclusion that the inline ++ doesn't work (in Javascript as a whole ? Or simply in my example ?).
Here's a test with three pieces of code, it seems that ++ is ok with a variable but not inline.
So, no inline ++ for us in Javascript?
There's nothing particular to jQuery about this. ++ increments a variable. You are trying to increment the return value of a function call.
parseInt($('#TextBox').val()) + 1 working fine ?
++ performs an assignment , where are you changing a property/variable value here? It's for the same reason 1++ doesn't work and 1+1 does. See the language specification on the Postfix incremenet operator.
+ doesn't modify a variable.
+ 1 produces the value of one more, ++ post-increments (returning current value)Q: What does x++ mean?
A: x++ means take the value of x, let's call this n, then set x to be n + 1, then return n.
Q: Why does this fail on a non-variable?
A: Let's try it on something simple, say 3, and see where things go wrong.
Take the value of 3 and call it n, okay, n = 3
Set 3 to be n + 1, so 3 = 3 + 1, 3 = 4 this makes no sense! So if this step can't be done, the ++ operator can't be used.
++ works on variables, not directly on numbers
var c = parseInt($('#TextBox').val());
$('#TextBox').val( ++c );
Change the order from
var x = 0;
var result = x++;
result // 0
To
var x = 0;
var result = ++x;
result // 1
Then it will evaluate ++ before retrieving the value.
++works. What's wrong with+1?$('#TextBox').val(function(){ return parseInt(this.value, 10)+1; });+signs together in a confusing way that works, do it like this1 + + "5"; // 6