Validators in a single file

interface StringValidator {
  isAcceptable(s: string): boolean;
}
 
let lettersRegexp = /^[A-Za-z]+$/;
let numberRegexp = /^[0-9]+$/;
 
class LettersOnlyValidator implements StringValidator {
  isAcceptable(s: string) {
    return lettersRegexp.test(s);
  }
}
 
class ZipCodeValidator implements StringValidator {
  isAcceptable(s: string) {
    return s.length === 5 && numberRegexp.test(s);
  }
}
 
// Some samples to try
let strings = ["Hello", "98052", "101"];
 
// Validators to use
let validators: { [s: string]: StringValidator; } = {};
validators["ZIP code"] = new ZipCodeValidator();
validators["Letters only"] = new LettersOnlyValidator();
 
// Show whether each string passed each validator
for (let s of strings) {
  for (let name in validators) {
    let isMatch = validators[name].isAcceptable(s);
    console.log(`'${ s }' ${ isMatch ? "matches" : "does not match" } '${ name }'.`);
  }
}

Links:

https://www.typescriptlang.org/docs/handbook/namespaces.html#validators-in-a-single-file

doc_TypeScript

2025-01-10 15:47:30

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