Echo and print and print_r function Differences _php Tutorial

This article introduces the differences between the three output functions echo and print and Print_r, let's take a look at the usage speed issue.

The difference between 1.echo and print

The functions of Echo and print in PHP are basically the same (output), but there are subtle differences between the two. There is no return value after the echo output, but print has a return value and returns Flase when its execution fails. It can therefore be used as a normal function, such as executing the following code after the variable "value will be 1."

$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 values to be returned, the Echo statement in the code is running more efficiently than the print statement.

ECHO has no return value; Print has a return value, and the return value of print is always 1.

An expression
Print can be used for complex expressions, and Echo is not. For example, print can be used for the following examples:

The code is as follows	Copy Code

Parameters
Echo can have multiple parameters, and print can have only one parameter.

echo if there are multiple parameters, apply commas separated, each parameter does not need parentheses, the correct wording is as follows:

The code is as follows	Copy Code
echo "Good", "for", "You";

Note that if ECHO has multiple parameters, it is wrong to use just one parenthesis to enclose all the arguments. The following syntax is incorrect:

The code is as follows	Copy Code
Echo ("Good", "for", "You");

Print can have only one parameter, such as:

The code is as follows	Copy Code
Print ("Good for You"); Print "Good for You";

Both Echo and print function as output strings. The main difference between Echo and print is that ECHO is faster than print because ECHO has no return value.

The Print_r () function is used only for output arrays.

The array contents of the Print_r function output in PHP are not listed. In order to make it more beautiful to output. For example, arrays have multiple layers. The segments are listed, and we can write this:

Example #1 Print_r () Example

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$a = Array (' a ' = = ' Apple ', ' B ' + = ' banana ', ' c ' = = Array (' x ', ' y ', ' z ')); Print_r ($a); ?> The above example would output: Array ( [A] = Apple [B] = Banana [c] = = Array ( [0] = X [1] = y [2] = Z ) )

http://www.bkjia.com/PHPjc/632227.html www.bkjia.com true http://www.bkjia.com/PHPjc/632227.html techarticle This article introduces the differences between the three output functions echo and print and Print_r, let's take a look at the usage speed issue. The difference between 1.echo and print is basically the same for the Echo and print functions in PHP (... ).

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