Problem Description
Given the length and width of a rectangle, we need to implement a PHP program to calculate its perimeter. A rectangle is an enclosed two-dimensional figure with 4 sides. The opposite sides are equal and parallel, and the angle formed by adjacent sides is equal to 90 degrees. The perimeter is the sum of all sides; in other words, the perimeter is twice the sum of length and width. In this tutorial, we will learn how to find the perimeter of a given rectangle in PHP using different methods.
Rectangle perimeter formula
The formula for the circumference of the rectangle is as follows:
$${perimeter = 2 × (length and width)}$$
Of:
- Long - Horizontal distance.
- Width - Vertical distance.
Example
Let's understand the problem description with some input and output examples.
Enter
<code>長(zhǎng) = 10 單位 寬 = 5 單位</code>
Output
<code>30 單位</code>
Explanation
Calculate the circumference using the formula: 2 × (length and width).
<code>周長(zhǎng) = 2 × (10 + 5) = 2 × (15) = 30 單位</code>
Enter
<code>長(zhǎng) = 20 單位 寬 = 0 單位</code>
Output
<code>0</code>
Explanation
If the length or width of any dimension is zero, the two-dimensional figure does not exist. Therefore, a non-existent rectangular figure has no perimeter.
Enter
<code>長(zhǎng) = 15 單位 寬 = 10 單位</code>
Output
<code>50 單位</code>
Explanation
Calculate the circumference using formula: 2 × (length and width)
<code>2 × (15 + 10) 2 × (25) 50 單位</code>
Method 1: Direct formula method
We use the direct formula method to calculate the perimeter of a rectangle using PHP. The formula for calculating the circumference of a rectangle is: length, width, length, width
Formula for rectangle perimeter = 2 × (length and width). Return the result after calculating the perimeter.
Implementation steps
Accounting the following steps:
- Prefer length and width as input parameters.
- Calculate the circumference of a rectangle using formula: 2 × (length and width)
- After the calculation is completed, print the result.
Example
The following example is an implementation in PHP following the implementation steps discussed above.
<?php $length = 10; $width = 5; // 使用公式計(jì)算周長(zhǎng) $perimeter = 2 * ($length + $width); // 輸出 echo "長(zhǎng)為 $length,寬為 $width 的矩形的周長(zhǎng)是:$perimeter<br>"; ?>
Output
<code>長(zhǎng)為 10,寬為 5 的矩形的周長(zhǎng)是:30</code>
Time complexity: O(1), constant time Space complexity: O(1), constant space.
Method 2: Use the function
We will use a function to calculate the perimeter of the rectangle. The logic and formula for calculating the circumference of a rectangle are the same. We will use a function so that the code can be reused later by simply changing the value.
Implementation steps
Accounting the following steps:
- We create a function to calculate the perimeter, which uses the formula ${2 * ($length $width)}$ to calculate the perimeter of the rectangle.
- We pass the input value length and width.
- Finally, we output the result.
Example
The following example is an implementation in PHP following the implementation steps discussed above.
<code>長(zhǎng) = 10 單位 寬 = 5 單位</code>
Output
<code>30 單位</code>
Time complexity: O(1), a single function call. Spatial complexity: O(1), because the above function only uses some variables.
The above is the detailed content of PHP program to find the perimeter of rectangle. For more information, please follow other related articles on the PHP Chinese website!

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