角动态ngPattern [英] Angular dynamic ngPattern

问题描述

我正在尝试实现动态ngPattern.

I'm trying to implement dynamic ngPattern.

当用户单击按钮或从下拉列表中选择一个值时，我的正则表达式会更改.

My regex changes when the user clicks on a button or selects a value from dropdown.

但是由于某种原因，这似乎不起作用.下面是代码.

But for some reason this doesnt seem to work. Below is the code.

 app.controller('testController',function(){

    $scope.pattern = new RegExp('^\w{1,10}$');

    $scope.changePattern = function () {
        $scope.pattern = new RegExp('^\d{5}$');
    };

 });

但是当我尝试类似的方法时，它会起作用.

But when i try something like this, it works.

    $scope.pattern = /^\w{1,10}$/;

    $scope.changePattern = function () {
        $scope.pattern = /^\d{5}$/;
    };

我不确定为什么不能使用新的RegExp().我必须使用新的RegExp()的原因是，我在JSON响应中将它作为字符串获取了.

I'm not sure why using new RegExp() is not working. The reason I had to use new RegExp() is that I get this in a JSON response as string.

推荐答案

这是因为反斜线(\)是一个特殊字符，在构造字符串时需要使用"\\"进行转义:

This is because backlash (\) is a special character that you need to escape with "\\" when you are constructing a string:

$scope.pattern = new RegExp('^\\w{1,10}$');

因此，这与RegExp或ng-pattern无关.

这篇关于角动态ngPattern的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！