多行正则表达式无法正常工作

Question

我正在尝试使用正则表达式来定位时间并向其中添加文本。 但是当输入字符串有换行符时，我的正则表达式有问题。 如果我删除中断并测试该表达式，它将起作用。

另外，找到目标时间后，如何在目标时间前后添加文字？

var str = "00:00:01.120
In this lesson, we will learn how to determine the equation of a line, using the available information.

00:00:08.040
Let's look at the first example. Determine the equation of the line, that passes through the points (2, 5), and with the slope of 2. 

00:00:19.000
To begin, we should know that the equation of a line can be written in the form of y = mx + b, where m is the slope, and b is the y-intercept.";


    var patt1 = /(\d\d.\d\d.\d\d.\d\d\d)/gm;
    var result = str.match(patt1);

Answer 1

正如其他人指出的那样，您需要首先修复多行字符串。

完成此操作后，您可以使用replace方法而不是match方法在匹配时间前后添加文本：

var str = "00:00:01.120\n\
In this lesson, we will learn how to determine the equation of a line, using the available information.\n\
\n\
00:00:08.040\n\
Let's look at the first example. Determine the equation of the line, that passes through the points (2, 5), and\ with the slope of 2.\n\
\n\
00:00:19.000\n\
To begin, we should know that the equation of a line can be written in the form of y = mx + b, where m is the\ slope, and b is the y-intercept.";


var patt1 = /(\d\d.\d\d.\d\d.\d\d\d)/gm;
//var result = str.match(patt1);
var result = str.replace(patt1, "<some text>\$1<some other text>");
alert(result);

您可以在小提琴中尝试一下。

有关replace方法的更多信息，请查看MDN的参考页 。

Answer 2

您为str分配值的方式不正确。 您的浏览器必须阻止了您的脚本，因此从未进行过解析。

您可以按如下所示用\\ r \\ n替换换行符，

var str = "00:00:01.120\r\nIn this lesson, we will learn how to determine the equation of a line, using the available information.\r\n00:00:08.040\r\nLet's look at the first example. Determine the equation of the line, that passes through the points (2, 5), and with the slope of 2.\r\n00:00:19.000\r\nTo begin, we should know that the equation of a line can be written in the form of y = mx + b, where m is the slope, and b is the y-intercept.";

您可以检查该小提琴以了解其工作原理。