how to add validation using regex in javascript?-CodePudding

I am using regex to validate my logic. My regex is to allow all character or words except on word naveen.

I tried like this

let str = "123";
let str2 ="naveen"  // special case Exact naveen text not allow .
let str3 ="naddn"
let str4 ="nad$$dn"
let str5 ="naveen56"

let pattern = /[a-z] /;
let result1 = str.match(pattern);
let result2 = str2.match(pattern);
let result3 = str3.match(pattern);
let result4 = str4.match(pattern);
let result5 = str5.match(pattern);

console.log(result1)  // expected null   // correct
console.log(result2)  // expected null  // current showing  naveen text (INCORRECT)
console.log(result3)  // expected naddn   // correct
console.log(result4)  // expected nad$$dn   // correct
console.log(result5)  // expected naveen56 // correct

is there any way to fix this issue ?

here is my code https://jsfiddle.net/ac3m052y/

CodePudding user response：

You don't need a regex, a simple string compare will do. Here is an example with string compare and regex compare:

const input = [
  "123",
  "naveen",  // special case Exact naveen text not allow
  "naddn",
  "nad$$dn",
  "naveen56"
].forEach(str => {
  let strResult = (str === 'naveen') ? 'not allowed' : 'Ok'
  let regexResult = (/^naveen$/.test(str)) ? 'not allowed' : 'Ok'
  console.log(str   ' => '   strResult   ' (string compare), '   regexResult   ' (regex compare)')
});

Output:

123 => Ok (string compare), Ok (regex compare)
naveen => not allowed (string compare), not allowed (regex compare)
naddn => Ok (string compare), Ok (regex compare)
nad$$dn => Ok (string compare), Ok (regex compare)
naveen56 => Ok (string compare), Ok (regex compare)

CodePudding user response：

This code only check which "naveen" word. and I used php

if(!preg_match("/^((naveen))/", "naveen")){
echo "correct";
}else{
echo "incorrect";
}

CodePudding user response：

Result is this

let str = "123";
let str2 ="naveen"  // special case Exact naveen text not allow .
let str3 ="naddn"
let str4 ="nad$$dn"
let str5 ="naveen56"

let pattern = /^(naveen){1}$/;
let result1 = !pattern.test(str);
let result2 = !pattern.test(str2);
let result3 = !pattern.test(str3);
let result4 = !pattern.test(str4);
let result5 = !pattern.test(str5);

console.log(result1)  // expected null   // correct
console.log(result2)  // expected null  // not naveen text
console.log(result3)  // expected naddn
console.log(result4)  // expected nad$$dn
console.log(result5)  // expected naveen56