转换时间字符串格式 [英] convert time string format

问题描述

我想将时间数据转换为JavaScript中的HH:mm:ss格式. 我的代码有问题(请参见代码内的注释):

I want to convert time data to the format HH:mm:ss in JavaScript. I've got a problem in my code (see comments inside the code):

function parseTime(timeString){

    var timeString = timeString.toLowerCase();
    timeString = $.trim(timeString);

    var regEx = /^([0-9]|1[0-9]|2[0-3])$/;
    var regEx2 = /^([0-9]|1[0-9]|2[0-3])\.?([0-5][0-9])$/;
    var regEx3 = /^([0-9]|1[0-2])(a|p|am|pm)$/;
    var regEx4 = /^([1-9]|10|11|12)\.?([0-5][0-9])(a|p|am|pm)$/;

    if(regEx.test(timeString)){
        var hours = timeString;
        if(hours.length == 1){
            hours = '0' + hours;
        }
        return hours + ':00:00';
    }
    else if(regEx2.test(timeString)){
        var hoursEndIndex, minutesStartIndex;
        if(timeString.indexOf('.')){
            hoursEndIndex = timeString.indexOf('.');
            minutesStartIndex = timeString.indexOf('.') + 1;
        }else if(timeString.length == 3){//Problem here timeString.length returns 3 but the code below isn't executed?
            hoursEndIndex = 1;
            minutesStartIndex = 1;
        }else if(timeString.length == 4){//Same thing here?
            hoursEndIndex = 2;
            minutesStartIndex = 2;
            return timeString.length;
        }
        var hours = timeString.substring(0, hoursEndIndex);
        if(hours.length == 1){
            hours = '0' + hours;
        }
        var minutes = timeString.substr(minutesStartIndex, 2);
        return hours + ':' + minutes + ':00';
    }

推荐答案

我认为您正在使用 indexOf 此处错误:

I think you are using indexOf incorrectly here:

if(timeString.indexOf('.')){

从文档中:

返回可以在数组中找到给定元素的第一个索引；如果不存在，则返回-1.

Returns the first index at which a given element can be found in the array, or -1 if it is not present.

可能是这个意思:

if(timeString.indexOf('.') > -1) {

对于您的代码，即使字符串不包含点，第一个if语句中的表达式也将为true.这意味着else if语句将永远不会执行.

With your code the expression in the first if statement will be true even if the string does not contain a dot. This means that the else if statement will never be executed.

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