变量obj={name:“西蒙”,年龄:“20”,服装:{style:“简单”,嬉皮士:假}}for(obj中的var propt){console.log(propt+':'+obj[propt]);}

变量propt如何表示对象的财产?它不是内置方法或属性。为什么它会产生对象中的每个属性?


当前回答

如果运行Node,我建议:

Object.keys(obj).forEach((key, index) => {
    console.log(key);
});

其他回答

还添加了递归方式:

function iterate(obj) {
    // watch for objects we've already iterated so we won't end in endless cycle
    // for cases like var foo = {}; foo.bar = foo; iterate(foo);
    var walked = [];
    var stack = [{obj: obj, stack: ''}];
    while(stack.length > 0)
    {
        var item = stack.pop();
        var obj = item.obj;
        for (var property in obj) {
            if (obj.hasOwnProperty(property)) {
                if (typeof obj[property] == "object") {
                  // check if we haven't iterated through the reference yet
                  var alreadyFound = false;
                  for(var i = 0; i < walked.length; i++)
                  {
                    if (walked[i] === obj[property])
                    {
                      alreadyFound = true;
                      break;
                    }
                  }
                  // new object reference
                  if (!alreadyFound)
                  {
                    walked.push(obj[property]);
                    stack.push({obj: obj[property], stack: item.stack + '.' + property});
                  }
                }
                else
                {
                    console.log(item.stack + '.' + property + "=" + obj[property]);
                }
            }
        }
    }
}

用法:

iterate({ foo: "foo", bar: { foo: "foo"} }); 
Object.keys(obj).forEach(key =>
  console.log(`key=${key} value=${obj[key]}`)
);
let obj = {"a": 3, "b": 2, "6": "a"}

Object.keys(obj).forEach((item) => {console.log("item", obj[item])})

// a
// 3
// 2

您可以使用for…访问对象的嵌套财产。。。in和forEach循环。

对于在:

for (const key in info) {
    console.log(info[key]);
}

对于每个:

Object.keys(info).forEach(function(prop) {
    console.log(info[prop]);
    // cities: Array[3], continent: "North America", images: Array[3], name: "Canada"
    // "prop" is the property name
    // "data[prop]" is the property value
});

for循环遍历对象的所有财产。propt在for循环的第一行中定义。它是一个字符串,是obj对象的属性的名称。在循环的第一次迭代中,propt将是“name”。