Javascript jquery - 从函数返回一个值

jquery - returning a value from function

提问by Michel Joanisse

say I have the following function:

说我有以下功能：

function checkPanes() {
    activePane = '';
    var panels = $("#slider .box .panel");

    panels.each(function() {

    //find the one in visible state.
    if ($(this).is(":visible")) {
    activePane = $(this).index()+1;
    console.log(activePane);
    }

    });
} //END checkPanes();

Ideally, I'd like to callon this function elsewhere (most likely from another function), and retrieve the value I am currently outputting to console.

理想情况下，我想在其他地方调用这个函数（很可能从另一个函数），并检索我当前输出到控制台的值。

(example ..)

（例子 ..）

function exampleCase() {
    checkPanes(); //evidently, does not return anything. 
    //Ideally, I want the numerical value, being output to console in above function.
}  

Thanks in advance! All suggestions / comments are well appreciated.
Cheers

提前致谢！非常感谢所有建议/意见。
干杯

回答by Jacob Mattison

Just noticed the loop; looks like what you may want to return is an array of all active panels (since in theory there could be more than one).

刚刚注意到循环；看起来您可能想要返回的是所有活动面板的数组（因为理论上可能不止一个）。

function checkPanes() {
    activePanes = [];
    var panels = $("#slider .box .panel");

    panels.each(function() {

    //find the one in visible state.
    if ($(this).is(":visible")) {
    activePane.push($(this).index()+1);
    console.log(activePane);
    }

    });
    return activePanes;
} 

If you know there will only ever be one active, you can go back to your original approach and just add return activePaneafter the console.log.

如果您知道永远只有一个活动，您可以回到原来的方法，只需return activePane在console.log.

回答by lsuarez

Forget everyone who says return activePanesince they didn't see it's in a jQuery eachloop. Won't work.

忘记那些说return activePane因为他们没有看到它在 jQueryeach循环中的人。不会工作。

I'd suggest restructuring your selector. The selector you should be using is: $("#slider .box .panel:visible"). This will cut out your each loop entirely. For instance you could restructure the code as follows:

我建议重组你的选择器。您应该使用的选择器是：$("#slider .box .panel:visible")。这将完全消除您的每个循环。例如，您可以按如下方式重构代码：

function checkPanes() {
    return $("#slider .box .panel:visible").index();
}

function exampleCase() {
    var visiblePane = checkPanes();

    // ... do something with the index
}

I'd suggest just using the selector in-line rather than making a new function, but that's a matter of taste, especially if you have to select the same thing in multiple places.

我建议只使用内嵌的选择器而不是创建一个新函数，但这是一个品味问题，尤其是如果您必须在多个地方选择相同的东西。

回答by Nicola Peluchetti

you have to return something inside the first function to manipulate it inside the second:

你必须在第一个函数中返回一些东西才能在第二个函数中操作它：

function checkPanes() {
    activePane = '';
    var panels = $("#slider .box .panel");
    //create a return array
    visiblePanels = [];
    panels.each(function() {

    //find the one in visible state.
    if ($(this).is(":visible")) {
    activePane = $(this).index()+1;
    //add the result to the returnb array
    visiblePanels[] = activePane
    }
    });
    // return results
    return visiblePanels;
}

function exampleCase() {
    var thepane = checkPanes();
    //now it has all the visible panels that were founded in the other function
    // you can access them with thepane[0] or iterate on them

}  

I think this is what you need.

我认为这就是你所需要的。

回答by Piotr Kula

You can keep your code and just add a return if you want to use the values somewhere else

如果您想在其他地方使用这些值，您可以保留您的代码并添加一个返回值

function checkPanes() {
 activePane = '';
 var panels = $("#slider .box .panel");

  panels.each(function() {

  //find the one in visible state.
  if ($(this).is(":visible")) {
  activePane = $(this).index()+1;
  console.log(activePane); //Logs to console.
  return activePane; //Returns value also.
}

});
} 

So in here you can either use the returned value or just have it log to console. Thats how i understood your question

因此，在这里您可以使用返回的值，也可以将其记录到控制台。我就是这样理解你的问题的

function exampleCase() {
    checkPanes(); //Now it will still write in console. but you dont need to use the return

    alert(checkpanes()); //Would write it to console and to an alert!
} 

But make sure you return string - or convert to string if you want to disaply it somewhere as text.

但是请确保您返回字符串 - 或者如果您想将它作为文本显示在某处，则转换为字符串。

回答by n00dle

Just switch your console line to a return statement:

只需将您的控制台行切换到 return 语句：

function checkPanes() {
    activePane = '';
    var panels = $("#slider .box .panel");

    panels.each(function() {

    //find the one in visible state.
    if ($(this).is(":visible")) {
        activePane = $(this).index()+1;
        return activePane; // Return the value and leave the function
    }

    });
} //END checkPanes();

To call:

致电：

function exampleCase() {
    var thepane = checkPanes(); //evidently, does not return anything. 
    // ...
}  

回答by pixelbobby

I think it's as easy as using return activePane;

我认为这就像使用一样简单 return activePane;

回答by ADW

This:

这个：

function checkPanes() {
  activePane = '';
  var panels = $("#slider .box .panel");

  panels.each(function() {

  //find the one in visible state.
  if ($(this).is(":visible")) {
  activePane = $(this).index()+1;
  }

  });
  return activePane;
} //END checkPanes();

and this:

和这个：

function exampleCase() {
   var myval=checkPanes(); //evidently, does not return anything. 
   console.log(myval);

}

}