在本文中，我們將學(xué)習(xí) PHP 中的數(shù)位交換。我們將學(xué)習(xí)如何定義交換、如何編寫程式碼來交換兩個數(shù)字、如何交換兩個以上數(shù)字和三個數(shù)字以及如何在有或沒有臨時變數(shù)的情況下交換數(shù)字等等。

開始您的免費軟體開發(fā)課程

網(wǎng)頁開發(fā)、程式語言、軟體測試及其他

讓我們先從定義開始。

「PHP 中的交換是一個定義為值交換的術(shù)語?！?/p>

交換兩個數(shù)字是使用或不使用臨時變數(shù)交換兩個值的過程。我希望這些例子對所有想要學(xué)習(xí)交換概念的程式設(shè)計師有所幫助。

如何在 PHP 中交換兩個數(shù)字？

交換號碼有兩種方法。這些數(shù)字包含數(shù)值。

• 用臨時變數(shù)交換兩個數(shù)字。
• 在沒有臨時變數(shù)的情況下交換兩個數(shù)字。

假設(shè)我們有一個變數(shù)的值為 10，

數(shù)字1 = 10;

另一個變數(shù)的值為 20，

數(shù)字2 = 20;

交換這兩個數(shù)字，結(jié)果應(yīng)該是，

數(shù)字1 =20

數(shù)字2= 10

這可以透過使用第三個臨時變數(shù)來實現(xiàn)，也可以不使用臨時變數(shù)。可以使用 +、-、* 和 / 運算子交換兩個數(shù)字。

1.用臨時變數(shù)交換兩個數(shù)字

代碼：

<?PHP
// Example of swapping of two numbers using a temporary variable
// Declaring two variables
$num1 = 100;
$num2 = 200;
// using echo statement print the variables before swapping two numbers
echo "<br>"."Before Swap";
echo "<hr>";
echo "<br>"."Value of first number is ?= ". $num1;
echo "<br>"."Value of second number is ?= ". $num2;
echo "<hr>";
// declaring temporary variable to be zero
$temp = 0;
// performing swap of numbers
$temp = $num1;
$num1 = $num2;
$num2 = $temp;
//using the echo statement print the variables after swapping the numbers
echo "<br>"."After Swap";
echo "<hr>";
echo "<br>"."Value of first number is ?= ". $num1;
echo "<br>"."Value of second number is ?= ". $num2;
?>

輸出:

2.不使用臨時變數(shù)交換兩個數(shù)字

代碼：

<?php
// Example of swapping of two numbers without using a temporary variable
// Declaring two variables
$num1 = 100;
$num2 = 200;
// using echo statemnt print the variables before swapping two numbers
echo "<br>"."Swap done without using temparory variable";
echo "<hr>";
echo "<br>"."Before Swap";
echo "<hr>";
echo "<br>"."Value of first number is ?= ". $num1;
echo "<br>"."Value of second number is ?= ". $num2;
echo "<hr>";
// performing swap of numbers
$num1 = $num1 - $num2;
$num2 = $num1 + $num2;
$num1 = $num2 - $num1;
//using the echo statement print the variables after swapping the numbers
echo "<br>"."After Swap";
echo "<hr>";
echo "<br>"."Value of first number is ?= ". $num1;
echo "<br>"."Value of second number is ?= ". $num2;
?>

輸出：

3.使用 list() 和 array() 等函數(shù)交換兩個數(shù)字

代碼：

<?php
// Example of swapping of two numbers using list() with array()
// Declaring two variables
$num1 = 100;
$num2 = 200;
// using echo statement print the variables before swapping two numbers
echo "<br>"."Swap done without using predefined functions";
echo "<hr>";
echo "<br>"."Before Swap";
echo "<hr>";
echo "<br>"."Value of first number is ?= ". $num1;
echo "<br>"."Value of second number is ?= ". $num2;
echo "<hr>";
// performing swap of numbers
list($num1, $num2) = array($num2, $num1);
//using the echo statement print the variables after swapping the numbers
echo "<br>"."After Swap";
echo "<hr>";
echo "<br>"."Value of first number is ?= ". $num1;
echo "<br>"."Value of second number is ?= ". $num2;
?>

輸出：

如何在 PHP 中交換三個數(shù)字？

交換號碼有兩種方法。這些數(shù)字包含數(shù)值。

• 用臨時變數(shù)交換三個數(shù)字。
• 在沒有臨時變數(shù)的情況下交換三個數(shù)字。

1.使用臨時變數(shù)交換三個數(shù)字

現(xiàn)在我們已經(jīng)學(xué)會了兩個數(shù)字的交換，我們已經(jīng)學(xué)會了三個數(shù)字的交換。以下範例示範了臨時（temp）變數(shù)如何交換三個數(shù)字。

代碼：

<?php
// Example of swapping three numbers using temporary variable
// Declaring three variables
$num1 = 100;
$num2 = 200;
$num3 = 300;
// using echo statement print the variables before swapping three numbers
echo "<br>"."Swap done without using temporary variable";
echo "<hr>";
echo "<br>"."Before Swap";
echo "<hr>";
echo "<br>"."Value of first number is ?= ". $num1;
echo "<br>"."Value of second number is ?= ". $num2;
echo "<br>"."Value of third number is ?= ". $num3;
echo "<hr>";
// performing swap of numbers
//assign first number the total of three numbers
$temp = $num1;
$num1 = $num2;
$num2 = $num3;
$num3 = $temp;
//using the echo statement print the variables after swapping the numbers
echo "<br>"."After Swap";
echo "<hr>";
echo "<br>"."Value of first number is ?= ". $num1;
echo "<br>"."Value of second number is ?= ". $num2;
echo "<br>"."Value of third number is ?= ". $num3;
?>

輸出：

2.不使用臨時變數(shù)交換三個數(shù)字

邏輯是計算總和並將其分配給 $num1 變數(shù)。

然後，

計算$num1的值，將該值賦給$num2，

計算$num2的值，將該值賦給$num3，

計算$num3的值，並將這個值再賦給$num1。

代碼：

<?php
// Declaring three variables
$num1 = 100;
$num2 = 200;
$num3 = 300;
// using echo statement print the variables before swapping three numbers
echo "<br>"."Swap done without using temporary variable";
echo "<hr>";
echo "<br>"."Before Swap";
echo "<hr>";
echo "<br>"."Value of first number is ?= ". $num1;
echo "<br>"."Value of second number is ?= ". $num2;
echo "<br>"."Value of third number is ?= ". $num3;
echo "<hr>";
// performing swap of numbers
//assign first number the total of three numbers
$num1 = $num1 + $num2 + $num3;
$num2 = $num1 - ($num2 + $num3);
$num3 = $num1 - ($num2 + $num3);
$num1 = $num1 - ($num2 + $num3);
//using the echo statement print the variables after swapping the numbers
echo "<br>"."After Swap";
echo "<hr>";
echo "<br>"."Value of first number is ?= ". $num1;
echo "<br>"."Value of second number is ?= ". $num2;
echo "<br>"."Value of third number is ?= ". $num3;
?>

輸出：

結(jié)論 – PHP 中的交換

希望這篇文章對所有希望學(xué)習(xí)數(shù)位交換的程式設(shè)計師有所幫助。本文提供了兩個和三個數(shù)字的交換以及適當(dāng)?shù)墓犂?。如果練?xí)這些範例，將幫助您理解概念並幫助您記住邏輯。

以上是PHP 中的交換的詳細內(nèi)容。更多資訊請關(guān)注PHP中文網(wǎng)其他相關(guān)文章！