How to find reverse of a number using custom pipes?

Bhawna Kaushik

Hello Everyone,

Please help me to find the reverse of a number using custom pipes in angular, i.e. whenever someone type in the textbox then below that reverse of that number will be displayed.

3 Replies

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Mahesh Verma8y ago
Accepted answer
Hi Komal,

Use the below pipe, i hope it will help you out
@Pipe({name:'reverseNumber'})
export class reverseNumber implements PipeTransform{
  transform(value:number){
    let rev=0,d;
    while(value>0){
      d=value%10;
      rev=(rev*10)+d;
      value=(value/10)|0;
    }
    return rev;
  }
}
on html page, use
"text" [(ngModel)]="userNumber" placeholder="Enter any number">
{{userNumber|reverseNumber}}
+2
Bhawna Kaushik8y ago
Thanks a lot Mahesh Sir and Amit Sir, I am really grateful to both of you.
+1
Amit Kumar8y ago
Hi,
Create a transfor method which retrun the reverse no. find the logic.
transform(value: string): string {
    let newStr: string = "";
    for (var i = value.length - 1; i >= 0; i--) {
      newStr += value.charAt(i);
    }
    return newStr;
  }
Whole code.
import { Pipe, PipeTransform } from '@angular/core';

@Pipe({name: 'reverseStr'})
export class ReverseStr implements PipeTransform {
  transform(value: string): string {
    let newStr: string = "";
    for (var i = value.length - 1; i >= 0; i--) {
      newStr += value.charAt(i);
    }
    return newStr;
  }
}
+1