PHP String Exercise 3: 4 Ways to Convert String Size

Hello~ Today we continue to explain the knowledge of string series in PHP. We introduced it to you in the previous article "PHP String Exercise 2: Quickly Extract File Names from Strings" How to quickly extract file names from strings. This article will introduce to you 4 common methods for converting string sizes as mentioned in the title.

Suppose there is such a question, "How to write a PHP script to implement the functions: 1. Convert all strings to uppercase letters; 2. Convert all strings to lowercase letters; 3. Make the string Capitalize the first character of the string; 4. Capitalize the first character of all words in the string."

Let’s answer it in detail below:

First we create a PHP sample file, and then directly add the code:

<?php
//所有大写字母
print(strtoupper("the quick brown fox jumps over the lazy dog."))."<br>";
//所有的小写字母
print(strtolower("THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG"))."<br>";
// 将字符串的第一个字符改为大写
print(ucfirst("the quick brown fox jumps over the lazy dog."))."<br>";
// 将字符串中所有单词的第一个字符改为大写
print(ucwords("the quick brown fox jumps over the lazy dog."));

We run the file directly , look at the results:

Everyone should have seen it directly. Each of the four requirements in the above questions can be solved with just one function. Let’s follow. Let me introduce to you these four implementation methods:

1. The strtoupper() function is used to convert a string to uppercase, and the syntax is "strtoupper(string)".

2. The strtolower() function is used to convert a string to lowercase. The syntax is "strtolower(string)".

3. The ucfirst() function is used to convert the first character in a string to uppercase. The syntax is "ucfirst(string)".

4. The ucwords() function is used to convert the first character of each word in the string to uppercase. The syntax is "ucwords(string)".

Finally, I would like to recommend a classic course on our platform "PHP String Processing (Jade Girl Heart Sutra Edition)". It's free~ Come and learn!

The above is the detailed content of PHP String Exercise 3: 4 Ways to Convert String Size. For more information, please follow other related articles on the PHP Chinese website!