form的序列化，即将表单中的键值序列化为可提交的字符串

表单

   <form id="target">
       <select name="age">
            <option value="http://www.mamicode.com/age1">20</option>
            <option value="http://www.mamicode.com/age2" selected>21</option>
        </select>
        <input name="name" value="http://www.mamicode.com/Cynthia">
        <label>passsword</label>
        <input type="password" name="password" value="http://www.mamicode.com/123456">
        <input type="hidden" name="salery" value="http://www.mamicode.com/3333">
        <textarea name="description" cols="15" rows="5">description</textarea>
        <input type="checkbox" name="hobby" value="http://www.mamicode.com/football" checked> Football
        <input type="checkbox" name="hobby" value="http://www.mamicode.com/basketball"> Basketball
        <input type="radio" name="sex" value="http://www.mamicode.com/Female" checked> Female
        <input type="radio" name="sex" value="http://www.mamicode.com/Male"> Male
    </form>

方法一

        function serializeForm1(form){ 
            var setForm = ""; 
            for(var key in form){ 
                if(form.hasOwnProperty(key)){ 
                    setForm += ‘"‘+form[key].name+‘"‘+‘:‘+‘"‘+form[key].value + ‘"‘+‘,‘;
                }
            }
            setForm = "{" + setForm.slice(0,setForm.length -1) + "}";
            console.log(setForm);
            // console.log(JSON.parse(setForm));
            return JSON.parse(setForm);
        }
        
        // 调用
        var oForm = document.getElementById(‘target‘);
        console.log(serializeForm3(oForm));

结果：

方法二

          function serializeForm2(form) {
            var parts = [];
            for (var i = 0, i1 = form.elements.length; i < i1; i++) {
                var field = form.elements[i];
                switch (field.type) {
                    case ‘select-one‘:
                    case ‘select-multiple‘:
                        if (field.type.length) {
                            for (var j = 0, j1 = field.options.length; j < j1; j++) {
                                var option = field.options[j];
                                if (option.selected) {
                                    var optionValue = ‘‘;
                                    if (option.hasAttribute(‘value‘) && option.attributes[‘value‘].specified) {
                                        //specified表明是否有此属性，有的话返回true，若定义了此属性但尚未添加到元素中也返回true。
                                        optionValue = option.value;
                                    } else {
                                        optionValue = optionValue.text;
                                    }
                                    parts.push(encodeURIComponent(field.name) + ‘=‘ + encodeURIComponent(optionValue));
                                }
                            }
                        }
                        break;
                    case undefined:
                    case ‘file‘:
                    case ‘submit‘:
                    case ‘reset‘:
                    case ‘button‘:
                        break;
                    case ‘radio‘:
                    case ‘checkbox‘:
                        if(!field.checked){
                            break;
                        }else{
                            parts.push(encodeURIComponent(field.name) + ‘=‘ + encodeURIComponent(field.dataset[‘index‘]));
                            break;
                        }
                    default:
                        if(field.name.length){
                            parts.push(encodeURIComponent(field.name) + ‘=‘ + encodeURIComponent(field.value));
                        }
                }
            }
            return parts.join(‘&‘);
        }
        
        // 调用
        var oForm = document.getElementById(‘target‘);
                console.log(serializeForm2(oForm));

结果：

方法三

        function serializeForm3(form){
            if(!form||form.tagName.toUpperCase()!=‘FORM‘){
                return false;
            }
            var res=[];
            var tag,tagType,tagVal,tagName;
            for(var i=0;i<form.length;i++){
                tag=form[i];
                tagType=form[i].type;
                tagVal=form[i].value;
                tagName=form[i].name;  
                var reg1=/[‘textarea‘|‘text‘|‘passsword‘|‘label‘]/g;
                var reg2=/[‘radio‘|‘checkbox‘]/g;
                var reg3=/[‘select‘]/g;
                if(reg1.test(tagType)){
                    res.push(encodeURIComponent(tagName)+"="+encodeURIComponent(tagVal));
                }else if(reg2.test(tagType)&&tag.checked){
                    res.push(encodeURIComponent(tagName)+"="+encodeURIComponent(tagVal));   
                }else if(reg3.test(tagType)){
                    for(var j=0;j<tag.options.length;j++){
                        if(tag.options[j].selected){
                        res.push(encodeURIComponent(tagVal)+"="+encodeURIComponent(tag.options[j].value||tag.options[j].text));  
                        }
                    }
                }else{}
            }  
            return res.join(" & ");
        }
        
        // 调用
        var oForm = document.getElementById(‘target‘);
        console.log(serializeForm3(oForm));

结果：

js: 将 form表单序列化