print

    (PHP 4, PHP 5, PHP 7, PHP 8)

    print — Output a string

    Description

    print(string $expression): int

    Outputs expression.

    print is not a function but a language construct. Its argument is the expression following the print keyword, and is not delimited by parentheses.

    The major differences to echo are that print only accepts a single argument and always returns 1.

    Parameters

    expression

    The expression to be output. Non-string values will be coerced to strings, even when the strict_types directive is enabled.

    Return Values

    Returns 1, always.

    Examples

    Example #1 print examples

    <?php
    print "print does not require parentheses.";

    // No newline or space is added; the below outputs "helloworld" all on one line
    print "hello";
    print     "world";

    print     "This string spans
    multiple lines. The newlines will be
    output as well"    ;

    print     "This string spans\nmultiple lines. The newlines will be\noutput as well.";

    // The argument can be any expression which produces a string
    $foo = "example";
    print     "foo is $foo"; // foo is example

    $fruits = ["lemon", "orange", "banana"];
    print     implode(" and ", $fruits); // lemon and orange and banana

    // Non-string expressions are coerced to string, even if declare(strict_types=1) is used
    print 6 * 7; // 42

    // Because print has a return value, it can be used in expressions
    // The following outputs "hello world"
    if ( print "hello" ) {
    echo     " world";
    }

    // The following outputs "true"
    ( 1 === 1 ) ? print 'true' : print 'false';
    ?>

    Notes

    Note: Using with parentheses

    Surrounding the argument to print with parentheses will not raise a syntax error, and produces syntax which looks like a normal function call. However, this can be misleading, because the parentheses are actually part of the expression being output, not part of the print syntax itself.

    <?php
    print "hello";
    // outputs "hello"

    print("hello");
    // also outputs "hello", because ("hello") is a valid expression

    print(1 + 2) * 3;
    // outputs "9"; the parentheses cause 1+2 to be evaluated first, then 3*3
    // the print statement sees the whole expression as one argument

    if ( print("hello") && false ) {
    print     " - inside if";
    }
    else {
    print     " - inside else";
    }
    // outputs " - inside if"
    // the expression ("hello") && false is first evaluated, giving false
    // this is coerced to the empty string "" and printed
    // the print construct then returns 1, so code in the if block is run
    ?>

    When using print in a larger expression, placing both the keyword and its argument in parentheses may be necessary to give the intended result:

    <?php
    if ( (print "hello") && false ) {
    print     " - inside if";
    }
    else {
    print     " - inside else";
    }
    // outputs "hello - inside else"
    // unlike the previous example, the expression (print "hello") is evaluated first
    // after outputting "hello", print returns 1
    // since 1 && false is false, code in the else block is run

    print "hello " && print "world";
    // outputs "world1"; print "world" is evaluated first,
    // then the expression "hello " && 1 is passed to the left-hand print

    (print "hello ") && (print "world");
    // outputs "hello world"; the parentheses force the print expressions
    // to be evaluated before the &&
    ?>

    Note: Because this is a language construct and not a function, it cannot be called using variable functions, or named arguments.

    See Also

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    User Contributed Notes 3 notes

    up
    31
    user at example dot net
    16 years ago
    Be careful when using print. Since print is a language construct and not a function, the parentheses around the argument is not required.
    In fact, using parentheses can cause confusion with the syntax of a function and SHOULD be omited.

    Most would expect the following behavior:
    <?php
    if (print("foo") && print("bar")) {
    // "foo" and "bar" had been printed
    }
    ?>

    But since the parenthesis around the argument are not required, they are interpretet as part of the argument.
    This means that the argument of the first print is

    ("foo") && print("bar")

    and the argument of the second print is just

    ("bar")

    For the expected behavior of the first example, you need to write:
    <?php
    if ((print "foo") && (print "bar")) {
    // "foo" and "bar" had been printed
    }
    ?>
    up
    14
    danielxmorris @ gmail dotcom
    16 years ago
    I wrote a println function that determines whether a \n or a <br /> should be appended to the line depending on whether it's being executed in a shell or a browser window. People have probably thought of this before but I thought I'd post it anyway - it may help a couple of people.

    <?php
    function println ($string_message) {
    $_SERVER['SERVER_PROTOCOL'] ? print "$string_message<br />" : print "$string_message\n";
    }
    ?>

    Examples:

    Running in a browser:

    <?php println ("Hello, world!"); ?>
    Output: Hello, world!<br />

    Running in a shell:

    <?php println ("Hello, world!"); ?>
    Output: Hello, world!\n
    up
    2
    mark at manngo dot net
    11 months ago
    The other major difference with echo is that print returns a value, even it’s always 1.

    That might not look like much, but you can use print in another expression. Here are some examples:

    <?php
    rand    (0,1) ? print 'Hello' : print 'goodbye';
    print     PHP_EOL;
    print     'Hello ' and print 'goodbye';
    print     PHP_EOL;
    rand(0,1) or print 'whatever';
    ?>

    Here’s a more serious example:

    <?php
    function test() {
    return !!    rand(0,1);
    }
    test() or print 'failed';
    ?>
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