String Functions

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PHP Strings

String Functions

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Author: Harsha M V Published on: 18th Mar 2009

PHP Strings

String Functions:

print()

print function outputs a string

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Example:

int print (string $arg)

print() is not actually a real function (it is a language construct) so you are not required to use parentheses with its argument list.

Various Method of Using print:

Sample Code

<?php
print("Hello World")
print "print() also works without parentheses."
print "This spans
multiple lines. The newlines will be
output as well"
print "This spans multiple lines. The newlines will be n output as well."
print "escaping characters is done "Like this"."
print <<<END
This uses the "here document" syntax to output
multiple lines with $variable interpolation. Note
that the here document terminator must appear on a
line with just a semicolon no extra whitespace!
END //(USING HEREDOC)
print $foo //(Printing Variables)
?>

echo

echo — Output one or more strings

Example:

void echo ( string $arg1 $arg2 );

Outputs all parameters.

echo() is not actually a function (it is a language construct), so you are not required to use parentheses with it. echo() (unlike some other language constructs) does not behave like a function, so it cannot always be used in the context of a function. Additionally, if you want to pass more than one parameter to echo(), the parameters must not be enclosed within parentheses.

Various Method of Using echo:

Sample Code

<?php
echo "Hello World"
echo "This spans
multiple lines. The newlines will be
output as well"
echo "This spans multiple lines. The newlines will be n output as well."
echo "Escaping characters is done "Like this"."
echo $foo
echo $foo,$bar
echo <<<END
This uses the "here document" syntax to output
multiple lines with $variable interpolation. Note
that the here document terminator must appear on a
line with just a semicolon. no extra whitespace!
END
echo $some_var ? 'true': 'false'
?>

sprintf

sprintf returns a string produced according to the formatting string format. Type Specifier that says what type the argument data should be treated as. The conversion specifiers are useful to format or transform the values. Each conversion specifier starts with a single percent symbol%) and ends with a conversion character (one ofb, c,d,f,o,s, u,x, orX ). Please refer http://in2.php.net/manual/en/function.sprintf.php for complete list of specifiers along with descriptions.

Example

Sample Code

<?php
$str = "Hello"
$number = 123
$txt = sprintf("%s world. Day number %u",$str,$number)
echo $txt
?>

Output

Hello world. Day number 123

print_r:

Prints human-readable information about a variable

print_r (mixed $expression [, bool $return])

print_r() displays information about a variable in a way that's readable by humans. print_r(), var_dump() and var_export() will also show protected and private properties of objects with PHP 5. Static class members will not be shown. Remember that print_r() will move the array pointer to the end. Use reset() to bring it back to beginning. Main practical use of print_r() function is to output array values.

Example:

Sample Code

<?php
$a = array ('a' => 'apple', 'b' => 'banana', 'c' => array ('x', 'y', 'z'))
print_r ($a)
?>

Output:

Array
(
    [a] => apple
    [b] => banana
    [c] => Array
    (
        [0] => x
        [1] => y
        [2] => z
    )
)

var_dump:

Var_dump is used to get information about a variable. This function displays structured information about one or more expressions that includes its type and value. Arrays and objects are explored recursively with values indented to show structure. In PHP 5 all public, private and protected properties of objects will be returned in the output.

Example:

Sample Code

<?php
$a = array(1, 2, array("a", "b", "c"))
var_dump($a)
?>

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Output:

array(3) {
    [0]=>
    int(1)
    [1]=>
    int(2)
    [2]=>
        array(3) {
            [0]=>
            string(1) "a"
            [1]=>
            string(1) "b"
            [2]=>
            string(1) "c"
        }
}

The echo and print functions are similar is all aspects. The only difference between them is that when items are separated using a comma, the echo function performs faster.

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