How to determine if two values ​​are not equal in php

In PHP programming, it is often necessary to determine whether two values ​​are equal. Sometimes, we also need to know what to do when two values ​​are not equal. This article will introduce different ways to determine whether two values ​​are equal in PHP.

1. Use the inequality operator

In PHP, you can use the != operator to determine whether two variables are not equal. The following is a simple example:

$var1 = 10;
$var2 = 20;
if ($var1 != $var2) {
    echo "$var1 和 $var2 不相等";
}

In the above example, if the values ​​of the $var1 and $var2 variables are not equal, "10 and 20 are not equal" will be output.

2. Use the constant inequality operator

There is also a constant inequality operator !== in PHP, which can compare the values ​​of two variables at the same time. their data types. Here is an example:

$var1 = "10";
$var2 = 10;
if ($var1 !== $var2) {
    echo "$var1 和 $var2 不相等";
}

In this example, $var1 is assigned the string "10", and $var2 is assigned the number 10. Since their data types are different, $var1 !== $var2 will return true, thus outputting "10 and 10 are not equal".

3. Use function comparison

In addition to using operators, you can also use functions in PHP to compare the values ​​of two variables. For example, you can use the strcmp() function to compare the values ​​of two strings. The following is an example:

$str1 = "abc";
$str2 = "def";
if (strcmp($str1, $str2) !== 0) {
    echo "$str1 和 $str2 不相等";
}

In the above example, if the values ​​of strings $str1 and $str2 are not equal, the strcmp() function will return a value that is not equal to 0, thus outputting "abc and def not equal".

Summary

In PHP programming, there are many ways to determine whether two values ​​are equal. You can use the != operator, use the inequality operator !==, or use a function to compare two values. No matter which method you use, always remember to be consistent and choose the right method of judgment.

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