The difference between print_r and var_dump in php

print_r and var_dump are both PHP debugging functions, but they differ in output format, depth, and recursive handling: Output format: print_r is easier to read, var_dump output is more verbose. Depth: print_r default depth is 1, var_dump has no limit. Recursion: print_r indents the output layer by layer, and var_dump outputs the complete hierarchical structure.

The difference between print_r and var_dump

print_r and var_dump are functions used for debugging and outputting variable information in PHP , but there are some key differences between them:

Output format:

• print_r: The format of the output is similar to var_dump, but Easier to read. It indents arrays and objects and displays variable types and values.
• var_dump: The format of the output is more detailed and technical, suitable for debugging more complex data structures. It shows the variable's type, value, reference count, and other debugging information.

Output depth:

• print_r: The maximum depth of the output variable is 1 by default. Depth can be increased by passing true as the second argument.
• var_dump: There is no limit to the depth of output variables by default.

Recursion:

• print_r: For recursive data structures (such as nested arrays or objects), print_r will be Output in indentation layer by layer.
• var_dump: For recursive data structures, var_dump will output the complete hierarchy of the data structure, potentially resulting in very long output.

Return type:

• print_r: Returns a string containing the formatted output of the variable.
• var_dump: Returns null, no value is returned, and the output is displayed directly to the screen.

Usage scenarios:

• print_r: Used to check the structure and value of variables, especially suitable for viewing complex data structure.
• var_dump: Used to debug deep into data structures to understand complete details of variables.

In short, print_r is more suitable for quickly checking the value and structure of variables, while var_dump is more suitable for in-depth and complex debugging.

The above is the detailed content of The difference between print_r and var_dump in php. For more information, please follow other related articles on the PHP Chinese website!