Question

如何检查值是否为数字。如果是数值，则显示文本中心，否则保留文本。我想知道我的陈述有什么问题。

＆＃13;

 for (var l = 0; l < Object.keys(pods[i].data.summaryDetailedData).length; l++) {
                        contentHtml += "<tr>";

                        for (var m = 0; m < pods[i].data.columns.length; m++) {

                            for (var field in pods[i].data.summaryDetailedData[l]) {
                                var rowspan = (pods[i].data.summaryDetailedData[l].children !== undefined ? pods[i].data.summaryDetailedData[l].children.length : "");
                                rowspanMax = Math.max(rowspanMax, rowspan);

                                if (field === pods[i].data.columns[m]) {

                                    var preFix = pods[i].data.summaryDetailedData[l]["sPrefix"] !== undefined ? pods[i].data.summaryDetailedData[l]["sPrefix"] : "";
                                    var postFix = pods[i].data.summaryDetailedData[l]["sPostfix"] !== undefined ? pods[i].data.summaryDetailedData[l]["sPostfix"] : "";
                                    var value = pods[i].data.summaryDetailedData[l][field];
                                    if (value.toString().substr(0, 3) == "- 1") {
                                        value = "N/A";
                                    }
                                    var color = pods[i].data.summaryDetailedData[l][field + "_color"];
                                    if (colName[m] === "sLabel" && pods[i].data.summaryDetailedData[l].bStepThrough == true) {
                                        value = "<a href=\"#\" class=\"stepthrough\">" + value + "</a>";
                                    }
                                    color = color !== "" && color !== undefined ? " <span class=\"color\" style=\"background: #" + color + "\"></span>" : " <span class=\"color\"></span>";
                                    contentHtml += "<td rowspan1=\"" + 1 + "\" class=\"" + (rowspan !== "" && rowspan > 1 ? "groups" : "") + " " + (!isNaN(value) || (!isNaN(value.toString().substr(1, value.length)) || value == "N/A" || typeof value == Number) ? "text-center" : "text-left") + "\">" + value + (Number(value) ? preFix : "") + color + (!isNaN(value) ? postFix : "") + "</td>";
                                    if (rowspan > 1) {
                                        var rowspanContent = "<td rowspa1=\"" + rowspan + "\" class=\"" + (rowspan !== "" && rowspan > 1 ? "groups" : "") + " " + (!isNaN(value) || (!isNaN(value.toString().substr(1, value.length)) || value == "N/A" || typeof value == Number) ? "text-center" : "text-left") + "\">" + value + (Number(value) ? preFix : "") + color + (!isNaN(value) ? postFix : "") + "</td>";
                                    }

                                    if (field === "sLabel") {
                                        for (var child in pods[i].data.summaryDetailedData[l].children) {

                                            if (child > 0 && rowspan >= 2) {
                                                contentHtml += "</tr>";
                                                contentHtml += "<tr>";
                                                contentHtml += rowspanContent;
                                            }

＆＃13;

Answer 1

您使用typeof：

var ff=1.222; console.log(typeof ff) // number
(typeof ff == "number") // true
var ff="1.222"; console.log(typeof ff) // string
(typeof ff == "number") // false

或

使用toFixed方法，如果变量不是数字，则返回undefined，否则，数字对象将在其原型中定义函数，因此它将返回函数{{因此它本身就是一个数字。

（这有点像黑客，但它效率高，成本最低）

toFixed

Answer 2

使用Number.isFinite（value）：

 contentHtml += "<td class=\"" +  (Number.isFinite(value) ? "text-center" : "text-left" + "\">" ) + value + (Number.isFinite(value) ? preFix : "") + color + (Number.isFinite(value) ? postFix : "") + "</td>";

Answer 3

这是jQuery 3.0当前使用的检查：

function isNumeric(obj){
    // As of jQuery 3.0, isNumeric is limited to
    // strings and numbers (primitives or objects)
    // that can be coerced to finite numbers (gh-2662)
    var type = jQuery.type(obj);
    return (type === "number" || type === "string") &&
        // parseFloat NaNs numeric-cast false positives ("")
        // ...but misinterprets leading-number strings, particularly hex literals ("0x...")
        // subtraction forces infinities to NaN
        !isNaN(obj - parseFloat(obj));
}

所以如果你还是使用jQuery，为什么不使用内置的isNumeric（）函数呢？

如何检查值是否为数字

3 个答案: