Question 205909 in Javascript Question posted in
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Javascript – How to split a string before the first letter in it and after it

I need to get separate numbers + special characters + letters from a string with numbers, letters, and special characters. My attempt

var chars = str.slice(0, str.search(/[a-zA-Z]+/));
var numbs = str.replace(chars, '');

The code does not work in case there are no letters.
example of how it should work

'123.331abc' -> '123.331' + 'abc'
'12331abc123' -> '12331' + 'abc123'
Tags:

3

Answers


  1. 0 
    const test = "123.887azee7";
const firstLetterIndex = test.search(/[a-zA-Z]/); // return the index of the first letter found, "-1" otherwise

    then you just use String.prototype.substring()

    if (firstLetterIndex !== -1) {
    const firstSubstring = test.substring(0, firstLetterIndex); //  out put 123.887
    const secondSubstring = test.substring(firstLetterIndex); // output azee7
} else {
    console.log('no letters founed');
    // or do whatever you want
}
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  2. 0

    Match the first part, then .slice() to get the second:

    const [firstPart] = string.match(/^[^a-z]*/i);
const secondPart = string.slice(firstPart.length);

    ^[^a-z]* means 0 or more non-letter at the beginning. Due to the nature of the * quantifier, this will always match, resulting in a match array whose first element is the first part.

    Try it:

    console.config({ maximize: true });

const testcases = [
    '12331abc123',
    '123.331abc',
    'abc123',
    'abc',
    '123',
];

function splitBeforeFirstLetter(string) {
  const [firstPart] = string.match(/^[^a-z]*/i);
  const secondPart = string.slice(firstPart.length);
  
  return [firstPart, secondPart];
}

testcases.forEach(
  testcase => console.log(testcase, splitBeforeFirstLetter(testcase))
);
    <script src="https://gh-canon.github.io/stack-snippet-console/console.min.js"></script>
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  3. 0

    You can get the both parts with a regex only:

    const arr = [
  '123.331abc',
  '12331abc123'
];

const splitBeforeLetter = str => str.match(/([^A-Za-z]+)(.+)/).slice(1);

console.log(...arr.map(splitBeforeLetter));
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