Javascript jquery 检查字符串是否以 1234 开头

jquery check if string starts with 1234

提问by Dragan

Thanks for taking the time to answer my question.

感谢您抽出时间回答我的问题。

I want to check if a string has exactly 7 characters and starts with "1234". How do I do that?

我想检查一个字符串是否正好有 7 个字符并以“1234”开头。我怎么做？

I know of string.substring but am not sure if I shouold use regex or are there any other alternative. Thanks in advance!

我知道 string.substring 但我不确定我是否应该使用正则表达式或者还有其他选择。提前致谢！

回答by gilly3

Simple RegExp:

简单的正则表达式：

var isMatch = /^1234...$/.test(myString);

Or:

或者：

var isMatch = myString.length == 7 && myString.indexOf("1234") == 0;

Edit:Or:

编辑：或：

var isMatch = myString.length == 7 && myString.substr(0, 4) == "1234";