Monday, April 27, 2009

Some PHP Exercises

Write a PHP program to set your locale information to that of theUnited Kingdom and display the currency of the UK. Once you are done, set the locale information to default.

Sunday, April 26, 2009

The localeconvo() function

This function returns an array that contains local numeric and currency formatting information.

syntax: localconvo();


The array elements in the array returned by this function and their meanings are listed below:

[decimal_point] - Decimal point character

[thousands_sep] - Thousands separator

[int_curr_symbol] - Currency symbol (example: USD)

[currency_symbol] - Currency symbol (example: $)

[mon_decimal_point] - Monetary decimal point character

[mon_thousands_sep] - Monetary thousands separator

[positive_sign] - Positive value character

[negative_sign] - Negative value character

[int_frac_digits] - International fractional digits

[frac_digits] - Local fractional digits

[p_cs_precedes] - True (1) if currency symbol is placed in front of a positive value, False (0) if it is placed behind

[p_sep_by_space] - True (1) if there is a spaces between the currency symbol and a positive value, False (0) otherwise

[n_cs_precedes] - True (1) if currency symbol is placed in front of a negative value, False (0) if it is placed behind

[n_sep_by_space] - True (1) if there is a spaces between the currency symbol and a negative value, False (0) otherwise

[p_sign_posn] - Formatting options:
0 - Parentheses surround the quantity and currency symbol
1 - The + sign is placed in front of the quantity and currency symbol
2 - The + sign is placed after the quantity and currency symbol
3 - The + sign is placed immediately in front of the currency symbol
4 - The + sign is placed immediately after the currency symbol

[n_sign_posn] - Formatting options:
0 - Parentheses surround the quantity and currency symbol
1 - The - sign is placed in front of the quantity and currency symbol
2 - The - sign is placed after the quantity and currency symbol
3 - The - sign is placed immediately in front of the currency symbol
4 - The - sign is placed immediately after the currency symbol

[grouping] - Array displaying how numbers are grouped (example: 3 indicates 1 000 000)

[mon_grouping] - Array displaying how monetary numbers are grouped (example: 2 indicates 1
00 00 00)

Example input:

echo setlocale(LC_ALL,NULL);
print_r(localeconv());

Example output:

English_United States.1252Array ( [decimal_point] => . [thousands_sep] => , [int_curr_symbol] => USD [currency_symbol] => $ [mon_decimal_point] => . [mon_thousands_sep] => , [positive_sign] => [negative_sign] => - [int_frac_digits] => 2 [frac_digits] => 2 [p_cs_precedes] => 1 [p_sep_by_space] => 0 [n_cs_precedes] => 1 [n_sep_by_space] => 0 [p_sign_posn] => 3 [n_sign_posn] => 0 [grouping] => Array ( [0] => 3 ) [mon_grouping] => Array ( [0] => 3 ) )

Friday, April 24, 2009

Some PHP Exercises

What is the use of the setlocale() function?

Write a program to set your locale information to the UK and then revert back to your default locale information.

The setlocale() function

This function could be used to set locale information such as time, language, monetary and geographical information.

syntax: setlocale(constant, location);

constant – specifies what locale information should be set.
This parameter can contains the following values:
LC_ALL - All of the below
LC_COLLATE - Sort order
LC_CTYPE - Character classification and conversion (e.g. all characters should be lower or upper-case)
LC_MESSAGES - System message formatting
LC_MONETARY - Monetary/currency formatting
LC_NUMERIC - Numeric formatting
LC_TIME - Date and time formatting


location – This parameter specifies which location the locale information should be set for.

The location parameter can hold a string or an array. In case of a string, the country/region code needs to be specifued.

If you are passing an array, the setlocale() function will scan through each of the array elements until it finds a valid region or country code and sets locale information for that region or country.

In order to setyour default locale information , you could use

setlocale(LC_ALL,NULL);

Example input:

echo setlocale(LC_ALL,"En-Us");
In this example, we are setting the locale information to that of the US.

Example output:

English_United States.1252

Monday, April 20, 2009

The levenshtein() function

This function calculates the Levenshtein distance between two strings.

syntax: levenshtein(string1,string2[,insert,replace,delete]);

string1 and string2 are the two input strings.
insert- the cost of inserting a character
replace - the cost of replacing a character
delete - the cost of deleting a character

By default, the cost for each operation is 1. However, we could also mention a cost, in which case, the Levenshtein cost would be calculated accordingly.

Example input:

$str1 = "John";
$str2 = "COrney";
echo levenshtein($str1,$str2);
echo "
";
echo levenshtein($str1,$str2,1,2,3);


Example output:

5
8

What is Levenshtein distance?

The Levenshtein distance between two strings is the minimum number of operations required to convert one string to another.

The operations might include insert, replace or a delete.

Friday, April 17, 2009

Some PHP Exercises

  • Write a program using the count_chars() function and determine the ASCII values of all English alphabets.

  • How would you find the list of all characters that are not present in a string?

The count_chars() function

This function can be used to determine the characters in a string and the number of times they are used.

syntax: count_chars(string,mode);

string – the input string
mode

This parameter will determine the output of the count_chars() function.

Following are the possible values and implications of this parameter.
0 – The function returns an array with the ASCII value of every possible character as the key and the number of occurrances in the string as the value.

1 – The function returns anarray with the ASCII values as keys and the number of occurrances as values. In this case, the function creates an array element for characters that occur atleast once in the string.

2 - The function returns anarray with the ASCII values as keys and the number of occurrances as values. The array elements will correspond to characters that are not present in the string.

3 – The function will just display all the characters that are present in the input string.

4 – The function displays all the characters that are not present in the input string.


Example input:

$str = "Rooney";
echo $str;
echo "
";
print_r(count_chars($str,1));
echo "
";
echo count_chars($str,3);
echo "
";
echo count_chars($str,4);

Example output:

Rooney

Array ( [82] => 1 [101] => 1 [110] => 1 [111] => 2 [121] => 1 )

Renoy
******

Wednesday, January 7, 2009

UUEncoding and UUDecoding

convert_uuencode() function


This function encodes a string using the Unix-to-Unix encoding algorith.


syntax: convert_uuencode(string);

string – the input string

convert_uudecode() function

This function decodes a UU Encoded string.


snytax: convert_uudecode(string);

string – the encoded string

Example input:

$str = "This is Vince";
echo $str;
echo "";
echo convert_uuencode($str);
echo "";
echo convert_uudecode($encstr);

Example output:
This is Vince -5&AI

r!6:6yc90``>