What's the Difference Between `echo`, `print`, `print_r`, and `var_dump` in PHP?

Distinguishing between Echo, Print, Print_r, and Var_dump in PHP

Many PHP developers frequently utilize echo and print_r for outputting data. However, print, surprisingly, is rarely used. Despite their apparent similarities, these language constructs have distinct characteristics.

Echo vs. Print

Both echo and print primarily serve the purpose of displaying strings. However, there are some subtle differences between them:

• Print has a return value of 1, enabling its inclusion in expressions, while echo has a void return type.
• Echo allows multiple parameters, but this practice is uncommon.
• Echo marginally outperforms print in terms of speed.

As a general rule, echo is commonly preferred over print.

Var_dump vs. Print_r

Var_dump presents a comprehensive breakdown of a variable, including its type and sub-items (for arrays or objects). In contrast, print_r displays variables in a more user-friendly manner, omitting type information and simplifying array representation.

Var_dump generally proves more valuable during debugging, especially when dealing with unfamiliar variable types and values. For instance, consider the example:

$values = array(0, 0.0, false, '');

var_dump($values);
print_r ($values);

Print_r fails to differentiate between 0 and 0.0, or false and '':

array(4) {
  [0]=>
  int(0)
  [1]=>
  float(0)
  [2]=>
  bool(false)
  [3]=>
  string(0) ""
}

Array
(
    [0] => 0
    [1] => 0
    [2] => 
    [3] => 
)

The above is the detailed content of What's the Difference Between `echo`, `print`, `print_r`, and `var_dump` in PHP?. For more information, please follow other related articles on the PHP Chinese website!