print

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

print — Output a string

Опис

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.

Параметри

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

Значення, що повертаються

Returns 1, always.

Приклади

Приклад #1 print examples

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

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

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

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

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

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

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

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

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

Примітки

Зауваження: 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 && ?>

Зауваження: Оскільки це мовна конструкція, а не функція, її не можна викликати через змінні-функції або названі параметри.

Прогляньте також

echo - Output one or more strings
printf() - Output a formatted string
flush() - Flush system output buffer
Ways to specify literal strings