下面是我最喜欢的var_dump/print_r等效Javascript php var_dump。

function dump(arr,level) {
    var dumped_text = "";
    if(!level) level = 0;
    
    //The padding given at the beginning of the line.
    var level_padding = "";
    for(var j=0;j<level+1;j++) level_padding += "    ";
    
    if(typeof(arr) == 'object') { //Array/Hashes/Objects 
        for(var item in arr) {
        var value = arr[item];
            if(typeof(value) == 'object') { //If it is an array,
                dumped_text += level_padding + "'" + item + "' ...\n";
                dumped_text += dump(value,level+1);
            } else {
                dumped_text += level_padding + "'" + item + "' => \"" + value + "\"\n";
            }
        }
    } else { //Stings/Chars/Numbers etc.
        dumped_text = "===>"+arr+"<===("+typeof(arr)+")";
    }
    return dumped_text;
}

如果您使用的是firefox，那么firebug插件控制台是检查对象的绝佳方法

console.debug(myObject);

或者你可以像这样循环遍历属性(包括方法):

for (property in object) {
    // do what you want with property, object[property].value
}

这是我的解决方案。它很好地复制了var_dump的行为，并允许嵌套对象/数组。注意，它不支持多个参数。

function var_dump(variable) { let out = ""; let type = typeof variable; if(type == "object") { var realType; var length; if(variable instanceof Array) { realType = "array"; length = variable.length; } else { realType = "object"; length = Object.keys(variable).length; } out = `${realType}(${length}) {`; for (const [key, value] of Object.entries(variable)) { out += `\n [${key}]=>\n ${var_dump(value).replace(/\n/g, "\n ")}\n`; } out += "}"; } else if(type == "string") { out = `${type}(${type.length}) "${variable}"`; } else { out = `${type}(${variable.toString()})`; } return out; } console.log(var_dump(1.5)); console.log(var_dump("Hello!")); console.log(var_dump([])); console.log(var_dump([1,2,3,[1,2]])); console.log(var_dump({"a":"b"}));

我用了第一个答案，但我觉得里面少了一个递归。

结果是:

function dump(obj) {
    var out = '';
    for (var i in obj) {
        if(typeof obj[i] === 'object'){
            dump(obj[i]);
        }else{
            out += i + ": " + obj[i] + "\n";
        }
    }

    var pre = document.createElement('pre');
    pre.innerHTML = out;
    document.body.appendChild(pre);
}

如果使用Firebug，可以使用console.log输出一个对象，并在控制台中获得一个超链接的可浏览项。

基于之前在这篇文章中发现的函数。 增加递归模式和缩进。

function dump(v, s) {
  s = s || 1;
  var t = '';
  switch (typeof v) {
    case "object":
      t += "\n";
      for (var i in v) {
        t += Array(s).join(" ")+i+": ";
        t += dump(v[i], s+3);
      }
      break;
    default: //number, string, boolean, null, undefined 
      t += v+" ("+typeof v+")\n";
      break;
  }
  return t;
}

例子

var a = {
  b: 1,
  c: {
    d:1,
    e:2,
    d:3,
    c: {
      d:1,
      e:2,
      d:3
    }
  }
};

var d = dump(a);
console.log(d);
document.getElementById("#dump").innerHTML = "<pre>" + d + "</pre>";

结果

b: 1 (number)
c: 
   d: 3 (number)
   e: 2 (number)
   c: 
      d: 3 (number)
      e: 2 (number)