你可以通过显式地将一个条目分配给'undefined'来从你的映射中删除它。就像你的情况:

myArray[“lastname”] = undefined;

您正在使用Object，并且您一开始没有关联数组。使用关联数组，添加和删除项如下所示:

    Array.prototype.contains = function(obj)
    {
        var i = this.length;
        while (i--)
        {
            if (this[i] === obj)
            {
                return true;
            }
        }
        return false;
    }


    Array.prototype.add = function(key, value)
    {
        if(this.contains(key))
            this[key] = value;
        else
        {
            this.push(key);
            this[key] = value;
        }
    }


    Array.prototype.remove = function(key)
    {
        for(var i = 0; i < this.length; ++i)
        {
            if(this[i] == key)
            {
                this.splice(i, 1);
                return;
            }
        }
    }



    // Read a page's GET URL variables and return them as an associative array.
    function getUrlVars()
    {
        var vars = [], hash;
        var hashes = window.location.href.slice(window.location.href.indexOf('?') + 1).split('&');

        for(var i = 0; i < hashes.length; i++)
        {
            hash = hashes[i].split('=');
            vars.push(hash[0]);
            vars[hash[0]] = hash[1];
        }

        return vars;
    }


    function ForwardAndHideVariables() {
        var dictParameters = getUrlVars();

        dictParameters.add("mno", "pqr");
        dictParameters.add("mno", "stfu");

        dictParameters.remove("mno");


        for(var i = 0; i < dictParameters.length; i++)
        {
            var key = dictParameters[i];
            var value = dictParameters[key];
            alert(key + "=" + value);
        }
        // And now forward with HTTP-POST
        aa_post_to_url("Default.aspx", dictParameters);
    }


    function aa_post_to_url(path, params, method) {
        method = method || "post";

        var form = document.createElement("form");

        // Move the submit function to another variable
        // so that it doesn't get written over if a parameter name is 'submit'
        form._submit_function_ = form.submit;

        form.setAttribute("method", method);
        form.setAttribute("action", path);

        for(var i = 0; i < params.length; i++)
        {
            var key = params[i];

            var hiddenField = document.createElement("input");
            hiddenField.setAttribute("type", "hidden");
            hiddenField.setAttribute("name", key);
            hiddenField.setAttribute("value", params[key]);

            form.appendChild(hiddenField);
        }

        document.body.appendChild(form);
        form._submit_function_(); // Call the renamed function
    }

var myArray = newmyArray = new Object();
myArray["firstname"] = "Bob";
myArray["lastname"] = "Smith";
myArray["age"] = 25;

var s = JSON.stringify(myArray);

s.replace(/"lastname[^,}]+,/g, '');
newmyArray = JSON.parse(p);

不使用循环/迭代，我们也得到了相同的结果。

如果你想要一个更实用和优雅的方法，你可以这样做:

const o = { firstName: "foo", lastName: "bar" };
const { lastName, ...removed } = o;
lastName // bar
removed // { firstName: "foo" }

注意，如果对象中没有剩余项，则remove的值将是未定义的。

通过使用“delete”关键字，它将从JavaScript中的array中删除array元素。

例如,

考虑以下陈述。

var arrayElementToDelete = new Object();

arrayElementToDelete["id"]           = "XERTYB00G1";
arrayElementToDelete["first_name"]   = "Employee_one";
arrayElementToDelete["status"]       = "Active";

delete arrayElementToDelete["status"];

代码的最后一行将从数组中删除键为“status”的数组元素。

你可以通过显式地将一个条目分配给'undefined'来从你的映射中删除它。就像你的情况:

myArray[“lastname”] = undefined;