How to change the case of elements in php array

In PHP, there are many array functions that can be used to perform some common operations, such as adding, deleting, sorting, etc. Among them, some array functions can be used to uniformly modify the upper and lower case of the elements of the array. This article will explore how to use these functions to modify case in PHP.

1. strtoupper() and strtolower() functions

There are two functions in PHP that can convert all characters in a string to uppercase or lowercase: strtoupper() and strtolower(). These two functions can be used to modify the case of array elements. For example:

$words = array("Hello", "World", "Php");
$words_upper = array_map("strtoupper", $words);
$words_lower = array_map("strtolower", $words);
print_r($words_upper);
print_r($words_lower);

The above code will output:

Array
(
    [0] => HELLO
    [1] => WORLD
    [2] => PHP
)
Array
(
    [0] => hello
    [1] => world
    [2] => php
)

The above code uses the array_map() function to convert the elements in the $words array to uppercase or lowercase respectively, and stores the result in another In the two arrays $words_upper and $words_lower, the print_r() function is finally used to print them out.

2. ucfirst() and lcfirst() functions

In addition to converting all characters in the string to uppercase or lowercase respectively, you can also use the ucfirst() and lcfirst() functions to convert the first character of the string to uppercase or lowercase respectively. These two functions can also be used to modify the case of array elements. For example:

$words = array("php", "javascript", "html");
$words_ucfirst = array_map("ucfirst", $words);
$words_lcfirst = array_map("lcfirst", $words);
print_r($words_ucfirst);
print_r($words_lcfirst);

The above code will output:

Array
(
    [0] => Php
    [1] => Javascript
    [2] => Html
)
Array
(
    [0] => php
    [1] => javascript
    [2] => html
)

The above code uses the array_map() function to convert the first character of the element in the $words array to uppercase or lowercase respectively, and Store the results in two other arrays, $words_ucfirst and $words_lcfirst, and finally print them out using the print_r() function.

3. ucwords() function

PHP also provides a function ucwords(), which can convert the first letter of each word in the string to uppercase. Likewise, this function can also be used to change the case of array elements. For example:

$words = array("php programming", "javascript coding", "html5 development");
$words_ucwords = array_map("ucwords", $words);
print_r($words_ucwords);

The above code will output:

Array
(
    [0] => Php Programming
    [1] => Javascript Coding
    [2] => Html5 Development
)

The above code uses the array_map() function to convert the first letter of each word in the elements in the $words array to uppercase. , and store the result into the $words_ucwords array, and finally print it out using the print_r() function.

Summary:

In PHP, you can easily change the case of array elements using the strtoupper(), strtolower(), ucfirst(), lcfirst() and ucwords() functions. Revise. Through these functions, irregular text can be quickly converted into standardized upper and lower case forms in actual development, improving the readability and maintainability of the code.

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