Basic operations on C strings

String operation

String operation, which is described in two examples.

Example 1: pay for download)

# Include <stdio. h>

# Include <string. h>

// Print the string

Void display (char name [], char ch []);

Void main ()

{

Charch1 [40] = "hello world ";

Charch2 [40] = "I love you ";

Intlen = 0;

Intflag = 0;

Charch [10];

Display ("outputs =", outputs); // print the string

Display ("ch2 =", ch2); // print the string

/*********************************** Length function *** ****************************/

Len = strlen (bytes); // copy ch2 data to bytes

Printf ("len = % d \ n", len );

/*************************************** ***********************************/

/********************************** Comparison functions **** ******************************/

Flag = strcmp (forward, ch2 );

Printf ("flag = % d \ n", flag );

/*************************************** ***********************************/

/************************************ Truncation character function *** **************************/

// Strchr (substring, 'w'); // start from w and return a string

Display ("intercepted string:", strchr (substring, 'w'); // print the string

/*************************************** ***********************************/

/*********************************** Search character functions *** **************************/

Display ("searched string:", strstr (separator, "world"); // print the string

/*************************************** ***********************************/

/************************************ Truncation character function *** **************************/

// Cout <strpbrk (delimiter, "l") <endl;

Display ("starting from l:", strpbrk (substring, "l"); // starting from l

/*************************************** ***********************************/

Printf ("in \" he \ ", find the number of elements that belong to the sequence set: % d \ n", strspn (sequence, "he "));

/********************************** Additional functions **** ******************************/

Strcat (iterator, ch2); // copy ch2 data to iterator

Display ("outputs =", outputs); // print the string

/*************************************** *************************************/

/********************************** Copy function **** ********************************/

Strcpy (substring, ch2); // copy ch2 data to shard

Display ("outputs =", outputs); // print the string

/*************************************** *************************************/

}

// Print the string

Void display (char name [], char ch [])

{

Char * p, * q;

P = ch;

Q = name;

// Print the name first

While (* q! = '\ 0 ')

{

Printf ("% c", * q ++ );

}

// Print ch again

While (* p! = '\ 0 ')

{

Printf ("% c", * p ++ );

}

// Line feed

Printf ("\ n ");

}

Example 2: pay for download)

# Include <stdio. h>

# Include <string. h>

# Include <stdlib. h>

# Include <ctype. h>

Void main ()

{

Charch1 [] = "4.56 ";

Intinter;

Floatflo;

Doubledou;

Inter = atoi (bytes); // the string is converted to an integer and rounded up.

Printf ("inter = % d \ n", inter );

Flo = atof (outputs); // String Conversion to float

Printf ("flo = % f \ n", flo );

Dou = atof (random); // convert string to double

Printf ("dou = % lf \ n", dou );

If (isalpha ('A') // check whether it is a letter character

{

Printf ("letter \ n ");

}

If (isupper ('A') // check whether it is uppercase letters

{

Printf ("uppercase letters \ n ");

}

If (islower ('A') // check whether it is a lowercase letter

{

Printf ("lowercase letter \ n ");

}

If (isdigit ('5') // check whether the character is a number

{

Printf ("the character is a number \ n ");

}

If (isxdigit (0x34) // check whether it is a valid character represented by a hexadecimal number

{

Printf ("hexadecimal valid character \ n ");

}

If (isspace ('') // check whether it is a space character

{

Printf ("is a space character \ n ");

}

Printf ("% x: % s \ n", 0x0a, iscntrl (0x0d )? "Yes": "no"); // check whether it is a control character

If (ispunct (',') // check for punctuation

{

Printf ("punctuation \ n ");

}

If (isalnum ('4g') // check for letters and numbers

{

Printf ("letter and number \ n ");

}

If (isprint ('D') // check whether it is printable characters

{

Printf ("printable characters \ n ");

}

If (isgraph ('s) // check whether it is a graphical character, equivalent to isalnum () | ispunct ()

{

Printf ("is a graphical character \ n ");

}

}

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