Question

我希望防止多次选择相同的值，但值=“其他”只能进行多次选择

我的代码就像这样

function preventDupes( select, index ) {
var options = select.options,
    len = options.length;
while( len-- ) {
    //options[ len ].disabled = false;
}
//select.options[ index ].disabled = true;
if( index === select.selectedIndex ) {
    if(select.selectedIndex !== "Others"){
    if(select.selectedIndex != "") {
        alert('You\'ve already selected the item "' + select.options[index].text + '".\n\nPlease choose another.');
    }
    this.selectedIndex = 0; 
    }
} else if(index === "other") {



}
}

var f61 = select = document.getElementById( 'f61' );
var f62 = select = document.getElementById( 'f62' );
var f63 = select = document.getElementById( 'f63' );

f61.onchange = function() {
    preventDupes.call(this, f62, this.selectedIndex );
    preventDupes.call(this, f63, this.selectedIndex );
};
f62.onchange = function() {
    preventDupes.call(this, f61, this.selectedIndex );
    preventDupes.call(this, f63, this.selectedIndex );
};
f63.onchange = function() {
    preventDupes.call(this, f62, this.selectedIndex );
    preventDupes.call(this, f61, this.selectedIndex );
};

<select name="indication_subject[]" id="f61">
  <option value="" selected="selected">Subject </option>
  <option value="Accounting"> Accounting</option>
  <option value="Afrikaans"> Afrikaans</option>
  <option value="Arabic"> Arabic</option>
  <option value="other">Others</option>
</select>
<select name="indication_subject[]" id="f61">
  <option value="" selected="selected">Subject </option>
  <option value="Accounting"> Accounting</option>
  <option value="Afrikaans"> Afrikaans</option>
  <option value="Arabic"> Arabic</option>
  <option value="other">Others</option>
</select>
<select name="indication_subject[]" id="f63">
  <option value="" selected="selected">Subject </option>
  <option value="Accounting"> Accounting</option>
  <option value="Afrikaans"> Afrikaans</option>
  <option value="Arabic"> Arabic</option>
  <option value="other">Others</option>
</select>

对此有何看法？

Answer 1

JS是区分大小写的正如您所说的那样value="others"并且在您的代码中有书面

if(select.selectedIndex !== "Others")

检查并查看

Answer 2

在您链接的JavaScript代码中，您可能会更改

return $.inArray($(this).val(),arr)>-1;

为：

var value = $(this).val();
return $.inArray(value,arr)>-1 && value != 'other';

在您的代码中，有一个错误。

if(select.selectedIndex !== "Others"){

.selectedIndex是所选元素的整数索引，而不是字符串。相反，您可能需要.value。您应该阅读HTML select element's DOM上的文档。

阻止多个相同值的选择，但允许值可以是多个

2 个答案: