JavaScript variable scope question: to var, or not to var

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JavaScript变量范围问题:var,或不var

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Should I use window.variable or var?

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我应该使用window.variable还是var?

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当我点击按钮时,第一次,一切正常,但第二次,没有任何反应。 这是为什么? <form name="alert"><input type="text" name="hour"><input type="text" name="min"><input type="button" value="ok" onclick="budilnik(this.form)"> <script type="text/javascript"> function budilnik(form) { budilnik=1; min=form.min.value; hour=form.hour.value; alert (min+' '+hour+' '+budilnik); }

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Where to use "var' in javascript programs

Possible Duplicate: Difference between using var and not using var in JavaScript Hello, I am a self learned developer. Always, i write javascripts without the var for variables. But some javascripts use var for variables. Both worked well for me. I am bit confused by this. Is Writing scripts with var a standard form or they used only within classes ? var limits the scope of a varia

在javascript程序中何处使用“var”

可能重复: JavaScript中使用var和不使用var之间的区别 你好, 我是一位自学成才的开发者。 总是,我写的JavaScript没有var变量。 但是有些JavaScript使用var来表示变量。 两者对我都很好。 我有点困惑。 使用var标准形式编写脚本还是仅在类中使用? var将变量的范围限制为它声明的函数,如果你不使用var你创建一个全局变量。 全局趋向于导致难以维护并且受到竞争条件影响的代码。 除非你有一个非常好的理由

Is using 'var' to declare variables optional?

This question already has an answer here: What is the purpose of the var keyword and when should I use it (or omit it)? 18 answers They mean different things. If you use var the variable is declared within the scope you are in (eg of the function). If you don't use var , the variable bubbles up through the layers of scope until it encounters a variable by the given name or the global o

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IE11 Windows ajax调用不起作用

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