Javascript 解释jquery中的代码

我发现这个代码可以从扫描条形码中获取值

$(document).ready(function() {

    $(document).focus();

    var coba=[];
    $(document).on('keypress',function(e){
        coba.push(String.fromCharCode(e.which));                                    
        if (coba[coba.length-1]=="\r") {
          console.log(coba.join(''));  
          simpan(coba.join(''));
          coba = [];
        };
    }); 
});

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任何人都可以解释一下吗？

首先，我建议您访问jquery.com，看看他们的api文档和/或他们的学习中心

请参阅下面嵌入的注释。 这与条形码没有任何关系

//this is waiting until the browser has loaded the page and all the content
// the elements in the content are considered the DOM.
$(document).ready(function() {

    //this sets the focus to the window, it acts as if you had clicked
    // on a blank spot of the window.
    $(document).focus();

    //this sets up an empty array to hold characters that are being typed
    var coba=[];

    //this sets up the page so that, when a key is pressed it does something
    //the anonymous function below is is executed when a key is pressed
    $(document).on('keypress',function(e){

        //adds the character that was pressed to the array
        coba.push(String.fromCharCode(e.which));          

        //if the return key was pressed                          
        if (coba[coba.length-1]=="\r") {

          //print out the characters that were pressed on the browser console
          console.log(coba.join(''));  

          //this passes the string that was typed to a function
          // to a function named simpan -- can't tell you what that is
          // because it isn't a browser function.  Probably in a library
          simpan(coba.join(''));

          // empty out the array to wait for a new string to be typed
          coba = [];
        };
    }); 
});

如果这与读取条形码有关，则可能发生的情况是，连接到系统的条形码扫描仪的作用类似于键盘。 simpan函数可能由javascript库提供，甚至可能由硬件制造商提供

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祝你好运。

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