Javascript对捕获的正则表达式执行算术运算 [英] Javascript perform arithmetic on captured regexp

问题描述

我想将标题从默认名称替换为"*number* new messages | default"

I want to replace my title from its default to "*number* new messages | default"

这是我拥有的代码，它从默认更改为1 new messages很好，但从未超过1.

Here is the code I have, it changes from default to 1 new messages fine, but it never goes above 1.

title = $('title').text();
regexp = /^(\d+)/

if (title.match(regexp))
  $('title').text().replace(regexp, (parseInt("$1")+1).toString())
else
  $('title').text('1 New Messages | Default')

推荐答案

您应该将函数用作

You should be using a function as the second argument to replace, you also need to set the new value:

var title = $('title').text();
$('title').text(title.replace(regexp, function(m) { return parseInt(m, 10) + 1) }));

和往常一样，当您调用 parseInt ，否则您迟早会感到不愉快.

And, as usual, don't forget the radix argument when you call parseInt or you will be unpleasantly surprised sooner or later.

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