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This article mainly explains "what are the differences between echo, print and print_r in php". The content in the article is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn "what are the differences between echo, print and print_r in php?"

Differences: 1, echo has no return value, print return value is always 1, "print_r" is only returned when the parameter is set to "true"; 2, "print_r" is used to print variables, and echo and print are used to output one or more strings.

Operating environment of this tutorial: windows10 system, PHP7.1 version, DELL G3 computer

What is the difference between echo, print and print_r in php

Echo is a PHP statement, print and print_r are functions, a statement does not return a value, and a function can have a return value (even if it is not useful)

Print () can only print the value of a simple type variable (such as int,string)

Print_r () can print out the values of complex type variables (such as arrays, objects)

Echo outputs one or more strings

Print-- outputs a string

Description

Int print (string arg) / / the returned value is shaping

Print "Hello friend"

You can do the following

$name=print "nihao\ n"; $str = 'test print value is $name.'; eval_r ("\ $print=\" $str\ ";"); echo $print

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

Bool print_r (mixed expression_r [, bool return]) / / the return value is Boolean, the parameter is mix, and it can be a string, a shaping, an array, and the object class print_r () displays easy-to-understand information about a variable. If you give string, integer, or float, the variable value itself is printed. If array is given, the keys and elements will be displayed in a certain format. Object is similar to an array.

Print_r () will move the pointer of the array to the last edge.

You can

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

You can also use var_dump var_export

Echo-- outputs one or more strings

Description

Void echo (string arg1 [, string...]) / / the return value is empty echo "Hello", "friend"

Summary:

The functions of echo and print in PHP are basically the same (output), but there are slight differences between them. There is no return value after echo output, but print has a return value, which returns flase when its execution fails. So it can be used as a normal function, for example, the value of the variable $r will be 1 after executing the following code.

$r = print "Hello World"

This means that print can be used in some complex expressions, while echo is not. However, because the echo statement does not require any numeric values to be returned, the echo statement in the code runs slightly faster than the print statement.

Echo has no return value; print has a return value, and print always returns 1.

Thank you for your reading, the above is "what is the difference between echo, print and print_r in php?" after the study of this article, I believe you have a deeper understanding of the difference between echo, print and print_r in php, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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