javascript中的正则表达式，试图匹配但似乎不适用于$

Question

EDIT: This question is DIFFERENT. The regex works fine that everyone sent me. The problem is that the $ sign DOESN'T WORK on my string, but it works on others. I can't figure out why and I posted my function below.

I need to find a number at the end of a string, it will be like thisL

My Goal Amount: $25.00/$100.00.

I've tried

var matches = fileDataResult.match(/\d+$/);

but it returns null, I tried it without the $ and it returns the 25, without the .00.

How can I get a variable as a number for the first ones (25.00, with the decimals) and a different variable for the 100.00, with the decimals as well. I need the variables seperate so I can work on them, but I think regex is broken because it won't even work with the $ sign... anyone have suggestion? This is in javascript.

edit: here is my function, it reads a .txt file and gets the string. I can console.log the string just fine and it work, but it won't work when I use $ in regex!

function fileReaderFunc(file) {
    const fileReader = new FileReader();
    fileReader.onload = function() {
        let fileDataResult = '';
        const fileData = fileReader.result;
        fileDataResult = fileData.toString();

        console.log(fileDataResult);

        let str = fileDataResult;
        let reg = /\d+(\.\d+)?$/g;
        console.log(str.match(reg));
    };
    fileReader.readAsText(file);
}

Answer 1

First of all \\d+ do not match .

You can use this

\d+(\.\d+)?$

Explanation

• \\d+ - Matches one or more digits.
• (\\.\\d+)? Matches . followed by one or more digit. (? makes it optional )

 let str = "abc 125.00"; let reg = /\\d+(\\.\\d+)?$/g; console.log(str.match(reg)) 

Answer 2

 let str = "My Goal Amount: $25.00/$100.00."; str = str.substring(-1,str.length-1); // remove the terminal period let reg = /\\$.+\\$.+$/g; let res = str.match(reg); let arr = res[0].split('/'); let [num1,num2] = arr; console.log("1st: ", num1.substring(1, num1.length)); console.log("2nd: ", num2.substring(1, num2.length)); 

As it turns out this regex is simpler than one might suppose since the text itself includes dollar signs. One can construct a regex that searches for a literal dollar sign followed by other characters and then a second literal dollar sign also followed by other characters from the end of the string marked by a dollar sign symbol minus any slash which signifies the end of a string.

The match is stored in a result array containing one element whose string value is then split on the literal slash mark. The results are then stored in an array arr. Then the values stored in the array are assigned to variables num1 and num2 through array destructuring.

If you prefer a more focused regex, you can also code as follows:

 let s = "My Goal Amount: $25.00/$100.00."; s = s.substring(-1, s.length - 1); let reg = /\\$\\d+\\.\\d+.\\$\\d+\\.\\d+$/; let replaced = s.match(reg)[0].replace(/\\$/g, ""); console.log(replaced.split("/")); 

If you neglect to trim the string s of the terminal period, then the regex will not match with the string which results in a null. This regex specifies a pattern at the end of the string that starts with a dollar sign,followed by one or more digits then a period and one or more digits. The pattern continues with matching another character (in this case the slash mark) and then a dollar sign followed by one or more digits, next a period and again one or more digits.