PHP Exercises: Create a new string of the first half of a given string of even length

Last update on April 16 2025 12:55:42 (UTC/GMT +8 hours)

63. First Half of Even-Length String

Write a PHP program to create a new string of the first half of a given string of even length.

Sample Solution:

PHP Code :

<?php
// Define a function named 'test' that extracts the first half of a string
function test($s1)
{
    // Use substr to extract the substring from the beginning to the middle of s1
    return substr($s1, 0, strlen($s1) / 2);
}

// Test the 'test' function with different input strings and display the results
echo test("Hello")."\n";
echo test("Hi")."\n";
?>

Explanation:

Function Definition:

The function test is defined to take one parameter, $s1, which is expected to be a string.

Extract First Half of String:

The function calculates half the length of $s1 using strlen($s1) / 2.
It then uses substr($s1, 0, strlen($s1) / 2) to extract the substring from the beginning to the midpoint of $s1.

Return:

The function returns this substring, representing the first half of the original string.

Output:

He
H

Flowchart:

For more Practice: Solve these Related Problems:

Write a PHP script to create a new string consisting of the first half of an even-length input string.
Write a PHP function to slice an even-length string at its midpoint and return the left half.
Write a PHP program to validate that a string's length is even and then extract the first half as output.
Write a PHP script to compute the midpoint index and use substr to retrieve the leading segment of the string.

PHP Code Editor:

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