A method in C + + that determines whether a string is numeric:
cout <<"Please enter an array of integers (no more than 1000):"<<Endl
+ cin >> arr[0];
While (GetChar ()! = '\ n')
{
CIN >> Arr[num];
num++;
+ }
A method in Java that determines whether a string is a number: 1. The Java-brought function public static Boolean isnumeric (String str) {for (int i = 0; i < str.length (); i++) { System.out.println (Str.charat (i)); if (! Character.isdigit (Str.charat (i))) {return false; }} return true; }2. Use regular Expressions first to import Java.util.regex.Pattern and Java.util.regex.Matcherpublic boolean isnumeric (String str) {Pattern Patt Ern = Pattern.compile ("[0-9]*"); Matcher isnum = Pattern.matcher (str); if (!isnum.matches ()) {return false; } return true; }3. Using Org.apache.commons.langorg.apache.commons.lang.stringutils;boolean isnunicodedigits=stringutils.isnumeric ( "aaa123456789"); http://jakarta.apache.org/commons/lang/api-release/index.html the following explanation: Isnumericpublic static Boolean isnumeric (String str) Checks If the string contains only Unicode digits. A decimal point was not a Unicode digit and returns False.null would return false. An empty String ("") would return true. Stringutils.isnumeric (NULL) = False Stringutils.isnumeric ("") = True StringutiLs.isnumeric ("") = False Stringutils.isnumeric ("123") = True Stringutils.isnumeric ("3") = False Stringutils.isnume Ric ("AB2C") = False Stringutils.isnumeric ("12-3") = False Stringutils.isnumeric ("12.3") = False parameters:str-the Strin G to check, could be null returns:true if only contains digits, and is non-null above three ways, the second way is more flexible. The first to third way can only check the number without the minus sign "-", that is, enter a negative-199, the output will be false, and the second way you can modify the regular expression to implement the check negative, the regular expression is modified to "^-?" [0-9]+], modified to "-?" [0-9]+.? [0-9]+] to match all numbers.
Array of strings to determine numbers, alphabetic characters,