Differences between print (), print_r (), and echo () in php

This article describes the differences between the print (), print_r (), and echo () functions of php. we recommend this function to you. if you need it, refer to echo as a PHP statement, print and print_r are functions, and the statement does not return values. the function can return values (even if they are not used)

Print () can only print values of simple type variables (such as int and string)

Print_r () can print values of complex types of variables (such as arrays and objects)

Echo outputs one or more strings

Print -- output a string

Description

Int print (string arg) // The return value is an integer.

Print "your good friend ";

You can perform the following operations:

The code is as follows:

$ Name = print "nihao \ n ";
$ Str = 'Test print value is $ name .';
Eval_r ("\ $ print = \" $ str \";");
Echo $ print;

Print_r -- print easy-to-understand information about variables.

Bool print_r (mixed expression_r [, bool return]) // The return value is Boolean. the parameters are of the mix type, which can be strings, integers, arrays, and object classes print_r () displays easy-to-understand information about a variable. If the value is string, integer, or float, the variable value is printed. If array is provided, keys and elements are displayed in a certain format. Objects are similar to arrays.

Print_r () moves the array pointer to the last edge.

You can

The code is as follows:

Print_r (str );
Print_r (int );
Print_r (array );
Print_r (obj );

You can also use var_dump var_export.

Echo -- output one or more strings

Description

Void echo (string arg1 [, string...]) // the returned value is null.

Echo "Hello", "friend ";

Summary:

The echo and print functions in PHP are basically the same (output), but there are still slight differences between the two. No return value after echo output, but print has a return value. if the execution fails, flase is returned. Therefore, it can be used as a common function. for example, after the following code is executed, the value of $ r is 1.
$ R = print "Hello World ";
This means that print is available in some complex expressions, but echo is not. However, because the echo statement does not require any value to be returned, the running efficiency of the echo statement in the code is slightly faster than that of the print statement.

Echo does not return values; print has a return value, and print always returns 1.