PHP conversion function quick reference manual: Quickly query commonly used functions

PHP is a programming language widely used in Web development, which contains many functions related to data conversion. In order to facilitate developers to find and use these functions, the following is a PHP conversion function quick reference manual to quickly query commonly used data conversion functions and provide specific code examples.

1. String conversion function

a. strtoupper()

Function: Convert the string to uppercase.
Example:

$str = "hello world";
echo strtoupper($str); // 输出: HELLO WORLD

b. strtolower()

Function: Convert the string to lowercase.
Example:

$str = "HELLO WORLD";
echo strtolower($str); // 输出: hello world

c. ucfirst()

Function: Convert the first letter of the string to uppercase.
Example:

$str = "hello world";
echo ucfirst($str); // 输出: Hello world

2. Number conversion function

a. intval()

Function: Convert the variable Convert to integer.
Example:

$var = "123";
$intVar = intval($var);
echo $intVar; // 输出: 123

b. floatval()

Function: Convert the variable to a floating point number.
Example:

$var = "3.14";
$floatVar = floatval($var);
echo $floatVar; // 输出: 3.14

3. Array conversion function

a. json_encode()

Function: Convert array Convert to a JSON-formatted string.
Example:

$arr = array("name" => "John", "age" => 30);
$jsonStr = json_encode($arr);
echo $jsonStr; // 输出: {"name":"John","age":30}

b.json_decode()

Function: Convert a JSON format string to an array.
Example:

$jsonStr = '{"name":"John","age":30}';
$arr = json_decode($jsonStr, true);
print_r($arr); // 输出: Array([name] => John [age] => 30)

Conclusion

Listed above are only some commonly used data conversion functions in PHP. Through this manual, you can quickly find the ones you need. function and view specific code examples. In actual development, these conversion functions can help you process different types of data conveniently and improve development efficiency. I hope this manual can be helpful to your PHP development work!

The above is the detailed content of PHP conversion function quick reference manual: Quickly query commonly used functions. For more information, please follow other related articles on the PHP Chinese website!