php Exercise 3: Function Write a function named word_count that accepts a string as its parameter and returns the number of word
s in the string. A word is a sequence of one or more non-space characters (any character other than ' '). For example, the call of word_count("hello, how are you?") should return 4. Constraints: • Do not use any data structures such as arrays to help you solve this problem. • Do not use the String function explode on this problem. • But you can declare as many simple variables like Integer, String, etc. as you like. Keep it simple.
1 answer:
Answer:
<?php
function word_count($string){ // function that takes a string a parameter and returns the number of words in that string
$space = 0; // this variable is used in order to detect space, new line and tab spaces in a string
$words = 1; // this variable is used to identify word presence in string
$include = $space; //used to maintain the state of $words and $space
$counter = 0; // this counts the number of words in the string
$i = 0; //this moves through each character of the string
while ($i < strlen($string)){ // iterates through every character of string until the last character of string is reached
if ($string[$i] == " "||$string[$i] == "\n" || $string[$i] == "\t") //if the space or new line or tab space is identified in the string
$include = $space; //set the state of include as space if the next character is a space newline or a tab space
else if ($include == $space) { //if next character is a word and current state i.e. $include holds $space
$include = $words; // then set the state i.e. $include as $words
++$counter; } //increments i to move to next character at each iteration
++$i; } //returns the number of words in a string
return $counter; }
$str = "Hello, how are you "; //sample string
echo "Words: " . word_count($str); // calls word_count function to return number of words in str.
?>
Explanation:
The program has a function word_count that accepts a string as its parameter and returns the number of words in the string. In the function there are three variables $space and $words and $include used as state variables. For instance $space identifies space, new line and tab spaces in the $string so it specifies that a space has occurred. $words identifies words in the $string so it specifies that a word has occurred. $include holds this state information. $i moves through every character of the $string and when a space occurs in the $string then the state $include is set to $space. When a word occurs then state $include is set to $words. $counter variable, which is used to count the number of words is incremented to 1 when previous state is $space and next character is a word character. Every time a word is seen in the string, this variable is incremented to 1 to keep track of number of words in the string. When $i reaches the end of the string then this loop stops and counter returns the number of words in the $string.
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Answer:
I am writing a Python program that deletes players from the file whose names whose names do not begin with a vowel which means their names begin with a consonant instead. Since the SomePlayers.txt is not provided so i am creating this file. You can simply use this program on your own file.
fileobj= open('SomePlayers.txt', 'r')
player_names=[name.rstrip() for name in fileobj]
fileobj.close()
vowels = ('a', 'e', 'i', 'o', 'u','A','E','I','O','U')
player_names=[name for name in player_names
if name[0] in vowels]
fileobj.close()
print(player_names)
Explanation:
I will explain the program line by line.
First SomePlayers.txt is opened in r mode which is read mode using open() method. fileobj is the name of the file object created to access or manipulate the SomePlayers.txt file. Next a for loop is used to move through each string in the text file and rstrip() method is used to remove white spaces from the text file and stores the names in player_names. Next the file is closed using close() method. Next vowels holds the list of characters which are vowels including both the upper and lower case vowels.
player_names=[name for name in player_names
if name[0] in vowels]
This is the main line of the code. The for loop traverses through every name string in the text file SomePlayers.txt which was first stored in player_names when rstrip() method was used. Now the IF condition checks the first character of each name string. [0] is the index position of the first character of each players name. So the if condition checks if the first character of the name is a vowel or not. in keyword is used here to check if the vowel is included in the first character of every name in the file. This will separate all the names that begins with a vowel and stores in the list player_names. At the end the print statement print(player_names) displays all the names included in the player_names which begin with a vowel hence removing all those names do not begin with a vowel.
