2.1 determine which character a char contains, 2.1char

2.1 determine which character a char contains, 2.1char
Knowledge point:

1. char. IsControl

2. char. IsPunctuation

3. char. IsSurrogate

4. char. IsWhitespace

5. char. IsDigit

6. char. IsNumber

7. char. IsSeparation

8. char. IsSymbol

 

Problem:

There is a char type variable that you want to determine whether it contains letters, digits, numbers, punctuation marks, control characters, delimiters, blank spaces, or replacement characters. Similarly, a string variable may be used to determine the character at one or more positions in the string.

Solution

To determine a char value, you can use the built-in static method of the System. Char structure, as shown below:

1. char. IsControl

2. char. IsPunctuation

3. char. IsSurrogate

4. char. IsWhitespace

5. char. IsDigit

6. char. IsNumber

7. char. IsSeparation

8. char. IsSymbol

Using System; using System. collections. generic; using System. linq; using System. text; using System. threading. tasks; namespace _ 02 determine the characters in a Char {class Program {static void Main (string [] args) {Console. writeLine ("enter a character:"); string symbol = Console. readLine (); CharKind ck = GetCharKind (Convert. toChar (symbol); Console. writeLine (ck); string symbol1 = Console. readLine (); int position = Convert. toInt32 (Console. readLine (); CharKind ck1 = GetCharKindInString (symbol1, position); Console. writeLine (ck1); Console. readKey ();} public static CharKind GetCharKind (char theChar) {if (char. isLetter (theChar) {return CharKind. letter;} else if (char. isNumber (theChar) {return CharKind. number;} else if (char. isPunctuation (theChar) {return CharKind. punctuation;} else {return CharKind. unknown;} // determines the character type of a position in the string. public static CharKind GetCharKindInString (string theString, int CharPosition) {if (char. isLetter (theString, CharPosition) {return CharKind. letter;} else if (char. isNumber (theString, CharPosition) {return CharKind. number;} else if (char. isPunctuation (theString, CharPosition) {return CharKind. punctuation;} else {return CharKind. unknown ;}} public enum CharKind {Letter, Number, Punctuation, Unknown }}View Code

 

Verification Result 1 8 Number
Java determines whether a String contains a character char. For example, it determines whether "abcde" contains 'C '.

Print by yourself ~
String str = "abcd ";
If (str. indexOf (String. valueOf ('C') =-1 ){
// The string does not contain c
} Else {
// The String contains c, which is in the str. indexOf (String. valueOf ('C') position

Write a function char * strfind (char * s, char * t) in c ++ to find the position where string t appears for the first time in the string.

I personally think the char * of your return value is not reasonable, so I just modified it a little. Contact me if you have any questions. The program has been run!
# Include <iostream. h>
Int Strfind (char * s, char * t)
{
Int index, lengths = 0, lengtht = 0, I, j;
Char * Position;
While (s [lengths]! = 0) // obtain the length of string s
{
Lengths ++;
}
While (t [lengtht]! = 0)
{
Lengtht ++;
}
For (I = 0; I <lengths-lengtht; I ++) // cycle to the length of the source string minus the length of the target string.
{
Index = 0;
While (s [I + index] = t [index] & index <lengtht)
{
Index ++;
}
If (index = lengtht)
{
// Position = new char;
// * Position = I;
// Return Position;
Return I; // the position where I is returned.
}
}
// Position = NULL;
Return-1; // cannot be found
}
Int main ()
{
Char str1 [500];
Char str2 [500];
Cin> str1;
Cin> str2;
// Char * Position = Strfind (str1, str2 );
// Cout <* Position <endl;
Cout <Strfind (str1, str2) <endl;
Return 0;
}