如何以字符串格式显示JavaScript对象的内容,就像我们警告变量时一样?

与显示对象的格式相同。


当前回答

在NodeJS中,您可以使用util.inspect(obj)打印对象。请务必说明深度,否则只能打印出对象的浅层。

其他回答

我在项目中总是使用一个小助手函数,通过控制台进行简单、快速的调试。灵感来自拉雅维尔。

/**
 * @param variable mixed  The var to log to the console
 * @param varName string  Optional, will appear as a label before the var
 */
function dd(variable, varName) {
    var varNameOutput;

    varName = varName || '';
    varNameOutput = varName ? varName + ':' : '';

    console.warn(varNameOutput, variable, ' (' + (typeof variable) + ')');
}

用法

日(123.55);输出:

var obj = {field1: 'xyz', field2: 2016};
dd(obj, 'My Cool Obj'); 

使用此项:

console.log('print object: ' + JSON.stringify(session));

我需要一种递归打印对象的方法,pagewil提供了答案(谢谢!)。我对它进行了一点更新,以包括一种打印到某个级别的方法,并添加间距,以便根据当前级别正确缩进,以便更易于阅读。

// Recursive print of object
var print = function( o, maxLevel, level ) {
    if ( typeof level == "undefined" ) {
        level = 0;
    }
    if ( typeof level == "undefined" ) {
        maxLevel = 0;
    }

    var str = '';
    // Remove this if you don't want the pre tag, but make sure to remove
    // the close pre tag on the bottom as well
    if ( level == 0 ) {
        str = '<pre>';
    }

    var levelStr = '';
    for ( var x = 0; x < level; x++ ) {
        levelStr += '    ';
    }

    if ( maxLevel != 0 && level >= maxLevel ) {
        str += levelStr + '...</br>';
        return str;
    }

    for ( var p in o ) {
        if ( typeof o[p] == 'string' ) {
            str += levelStr +
                p + ': ' + o[p] + ' </br>';
        } else {
            str += levelStr +
                p + ': { </br>' + print( o[p], maxLevel, level + 1 ) + levelStr + '}</br>';
        }
    }

    // Remove this if you don't want the pre tag, but make sure to remove
    // the open pre tag on the top as well
    if ( level == 0 ) {
        str += '</pre>';
    }
    return str;
};

用法:

var pagewilsObject = {
    name: 'Wilson Page',
    contact: {
        email: 'wilson@hotmail.com',
        tel: '123456789'
    }  
}

// Recursive of whole object
$('body').append( print(pagewilsObject) ); 

// Recursive of myObject up to 1 level, will only show name 
// and that there is a contact object
$('body').append( print(pagewilsObject, 1) ); 

功能:

var print = function(o){
    var str='';

    for(var p in o){
        if(typeof o[p] == 'string'){
            str+= p + ': ' + o[p]+'; </br>';
        }else{
            str+= p + ': { </br>' + print(o[p]) + '}';
        }
    }

    return str;
}

用法:

var myObject = {
    name: 'Wilson Page',
    contact: {
        email: 'wilson@hotmail.com',
        tel: '123456789'
    }  
}

$('body').append( print(myObject) );

例子:

http://jsfiddle.net/WilsonPage/6eqMn/

我使用了pagewil的打印方法,效果非常好。

这是我的略微扩展版本,带有(草率的)缩进和不同的prop/ob分隔符:

var print = function(obj, delp, delo, ind){
    delp = delp!=null ? delp : "\t"; // property delimeter
    delo = delo!=null ? delo : "\n"; // object delimeter
    ind = ind!=null ? ind : " "; // indent; ind+ind geometric addition not great for deep objects
    var str='';

    for(var prop in obj){
        if(typeof obj[prop] == 'string' || typeof obj[prop] == 'number'){
          var q = typeof obj[prop] == 'string' ? "" : ""; // make this "'" to quote strings
          str += ind + prop + ': ' + q + obj[prop] + q + '; ' + delp;
        }else{
          str += ind + prop + ': {'+ delp + print(obj[prop],delp,delo,ind+ind) + ind + '}' + delo;
        }
    }
    return str;
};