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

If it is defined as char c = '\ 010', the number of characters in variable c is [10]

8. If it is defined as char c = '\ 010', the number of characters in variable c is [1 ].
The char type is 1 character;

9. If it is defined as: int x = 3, y = 2; float a = 2.5, B = 3.5; then the value of the following expression is [1]
(X + y) % 2 + (int) a/(int) B
(Int) a/(int) B = (int) (2/3) = 0

10. if the ASCII code of the letter a is 97 in decimal format and ch is a complex variable, the expression ch = 'A' + '8'-'3' is [f ].
Equivalent to 97 + 8-3 = 102, followed by 5 letters;

1. The putchar function can output a [D] to the terminal ].
A) integer variable expression B) Real Variable Value
C) string D) character or character variable value