Javascript，将 Nan 转换为 0.00 后验证值的问题

Question

最初，我有以下 javascript 来验证重量。但是要意识到有可能没有 selfDefinedGrid，这意味着权重将为 NaN。然后我添加了一个 if/else 语句来将 NaN 转换为 0.00。转换有效，但重量验证不再有效。请告知如何解决此问题，以便将 NaN 值转换为 0.00 并执行权重检查。

原文：

    $j( '#' + config.TableGridNames._02_SelfDefined + ' tbody tr td:nth-child(' + config.SelfDefinedGrid.Edit_Weight_Idx + ')' ).each( function ()
    {
        var row_index = $j( this ).closest( 'tr' ).index();
        /* skip over the header row; return is equivalent to continue */
        if ( row_index == 0 ) { return; }

        $j( this ).css( { 'background-color': 'white' } );
        var oWeight = $j( this ).find( 'input' );
        if ( !helper.isNumber( oWeight.val() ) || parseFloat( oWeight.val() ) < 0 || parseFloat( oWeight.val() ) > 1 )
        {
            $j( this ).css( { 'background-color': '#FFD1D1' } );
            blIsError = true;
        }

        decWeight = decWeight + parseFloat( oWeight.val() );
        console.log( 'Self-Defined (' + row_index.toString() + ') ' + decWeight.toString() );
    } );

更新：

    $j( '#' + config.TableGridNames._02_SelfDefined + ' tbody tr td:nth-child(' + config.SelfDefinedGrid.Edit_Weight_Idx + ')' ).each( function ()
    {
        var row_index = $j( this ).closest( 'tr' ).index();
        /* skip over the header row; return is equivalent to continue */
        if ( row_index == 0 ) { return; }

        $j( this ).css( { 'background-color': 'white' } );
        var oWeight = $j( this ).find( 'input' );

    if (oWeight.val() == 'NaN')
    {
    oWeight.val() = 0.00;
    }   else    {
            return oWeight.val();

        }

        if ( !helper.isNumber( oWeight.val() ) || parseFloat( oWeight.val() ) < 0 || parseFloat( oWeight.val() ) > 1 )
        {
            $j( this ).css( { 'background-color': '#FFD1D1' } );
            blIsError = true;
        }

        decWeight = decWeight + parseFloat( oWeight.val() );
        console.log( 'Self-Defined (' + row_index.toString() + ') ' + decWeight.toString() );
    } );

Answer 1

如果看起来您正试图将 0.0 分配给函数调用，那就是导致问题的原因。

if (oWeight.val() == 'NaN') {
    oWeight.val() = 0.0;
} else {
    return oWeight.val();
}

这是对上面代码的修复

let val = 0.0;
if (oWeight.val() == 'NaN') {
    val = 0.0;
} else {
    val = oWeight.val();
}

更紧凑的解决方案

let val = oWeight.val() == 'NaN' ? 0.0 : oWeight.val();

那么，在任一示例中，您都可以使用val 代替oWeight.val()