javascript中变量作用域的问题
好吧，我确实很困惑，为什么这不在文本区域返回 6。它不返回任何内容。 我认为这与 js 范围有关，但我无法弄清楚。
<body>
<script language="Javascript">
var broj = 5;
function Inci(){
var broj++;
document.frmMain.VrsteHolder.value = broj;
}
</script>
<form name="frmMain" method="get" action="script.php">
<textarea name="VrsteHolder" rows="4"> </textarea>
<input type="button" value="Dodaj porudzbinu" name="buttonDodaj" onClick="Inci();"/>
</form>
</body>
Ok I am definitely puzzled, why this is not returning 6 in textarea. It doesn't return anything.
I figured that it has something to do with js scopes, but i cant figure it out.
<body>
<script language="Javascript">
var broj = 5;
function Inci(){
var broj++;
document.frmMain.VrsteHolder.value = broj;
}
</script>
<form name="frmMain" method="get" action="script.php">
<textarea name="VrsteHolder" rows="4"> </textarea>
<input type="button" value="Dodaj porudzbinu" name="buttonDodaj" onClick="Inci();"/>
</form>
</body>
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删除
Inci函数内的var关键字。var重新声明当前范围内的变量，因此每次调用Inci都会重新声明broj。这将是正确的方法：
Get rid of the
varkeyword inside of theIncifunction.varredeclares variables in the current scope, so it will redeclarebrojevery invocation ofInci.This would be the correct way:
因为
var关键字定义了变量。从函数中删除var：because the
varkeyword defines the variable. Removevarfrom your function:问题是
var作为其他答案的详细信息，重新声明您的变量，或者尝试，并且实际上由于组合而引发语法错误。顺便说一句，虽然我看到的较少：不要忘记您可以通过使用 ++ 来增加并立即获得结果（增量运算符) 在变量之前，例如：
您可以在此处测试该版本。
The problem is
varas the other answers detail, redeclaring your variable, or attempting to rather, and actually throwing a syntax error because of the combination.As an aside though that I'm seeing less: don't forget you can increment and get the result immediately by having the ++ (increment operator) before the variable, for example:
You can test that version out here.