选择选项元素JavaScript控制台

Question

我想从列表JavaScript中选择100，我正在控制台中尝试

<div class="dataTables_length" id="Table_6_length">
 <label>
     <select name="DataTables_Table" aria-controls="DataTables_Table_6" class="form-control input-sm">
              <option value="10">10</option>
              <option value="25">25</option>
              <option value="50">50</option>
              <option value="100">100</option>
        </select>
</label></div>

我是JavaScript新手，请帮帮我

Answer 1

您可以像这样循环选择您的选项

let sel = document.getElementsByName('DataTables_Table')[0];

function getSelectedOption(sel) {
    var opt;
    for ( var i = 0, len = sel.options.length; i < len; i++ ) {
        opt = sel.options[i];
        if ( opt.value == 100 ) {
            break;
        }
    }
    return opt;
}

let opt100 = getSelectedOption(sel);
console.log(opt100)
console.log(opt100.value)

 let sel = document.getElementsByName('DataTables_Table')[0]; function getSelectedOption(sel) { var opt; for ( var i = 0, len = sel.options.length; i < len; i++ ) { opt = sel.options[i]; if ( opt.value == 100 ) { break; } } return opt; } let opt100 = getSelectedOption(sel); console.log(opt100) console.log(opt100.value) 

 <div class="dataTables_length" id="Table_6_length"> <label> <select name="DataTables_Table" aria-controls="DataTables_Table_6" class="form-control input-sm"> <option value="10">10</option> <option value="25">25</option> <option value="50">50</option> <option value="100">100</option> </select> </label></div> 

Answer 2

给select一个ID然后，它就像document.getElementById('selecter').value=100;一样简单document.getElementById('selecter').value=100;

请参考此。

Answer 3

您可以简单地使用.value属性作为dropdown element

 function selectOption(val) { document.getElementById('dataTable').value = val; } 

 <select name="DataTables_Table" id='dataTable' aria-controls="DataTables_Table_6" class="form-control input-sm"> <option value="10">10</option> <option value="25">25</option> <option value="50">50</option> <option value="100">100</option> </select> <button onclick='selectOption("100")'>select 100</button> <button onclick='selectOption("50")'>select 50</button> <button onclick='selectOption("25")'>select 25</button>