正则表达式检查JavaScript中的经/纬度

Question

I'm such a newb in regex, but still...
I based my test on this post.

I have this simple regex :

^-?([1]?[1-7][1-9]|[1]?[1-8][0]|[1-9]?[0-9])\.{1}\d{1,6}

In Debuggex , if I test it with 88.5 for example, it matches.

In my JS file, I have :

var lonRegex = new RegExp("^-?([1-8]?[1-9]|[1-9]0)\.{1}\d{1,6}");
var check = lonRegex.test(88.5); // hardcoded for demo
console.log(check) // output false

I can't guess why it's always returning me false, whatever the value is a number or a string like "88.5".

Answer 1

You will need to escape some characters when creating a RegExp object from a string. From MDN :

When using the constructor function, the normal string escape rules (preceding special characters with \\ when included in a string) are necessary.

In your case, this will work (note the double \\ for \\d and .):

var lonRegex = new RegExp("^-?([1-8]?[1-9]|[1-9]0)\\.{1}\\d{1,6}");
var check = lonRegex.test(88.5); // hardcoded for demo
console.log(check) // output true