JAVA

check if string has a valid number java

private boolean isInt(String s){
        try{
            Integer.parseInt(s);
            return true;
        }catch (NumberFormatException e){
            return false;
        }
    }

java how to check string is number

public static boolean isNumeric(String strNum) {
    if (strNum == null) {
        return false;
    }
    try {
        double d = Double.parseDouble(strNum);
    } catch (NumberFormatException nfe) {
        return false;
    }
    return true;
}

java program to Check given String is contians number or not

public class ContainsExample {
   public static void main(String args[]){
      String sample = "krishna64";
      char[] chars = sample.toCharArray();
      StringBuilder sb = new StringBuilder();
      for(char c : chars){
         if(Character.isDigit(c)){
            sb.append(c);
         }
      }
      System.out.println(sb);
   }