php string interpolation – PHP Variable Interpolation

php string interpolation – PHP String Interpolation, Using Variables in Strings. Use the string concatenation operator (.) when the value you want to include can’t be inside the string:

PHP string interpolation syntax

$user_str = 'and some more text';
$results = "This variable contains some text, $user_str";

// Result the interpolated variable
echo $results;

php string interpolation and Expressions Within Strings

print 'You have '.($_REQUEST['products'] + $_REQUEST['items']).' companmy.';
print "The word '$word' is ".strlen($word).' characters long.';
print 'You owe '.$amounts['payment'].' immediately';
print "My love's diameter is ".$love->getDiameter().' inches.';

We PHP, a string literal can be specified in main 4 ways,

  • Single quoted
  • Double quoted
  • Heredoc syntax
  • Nowdoc syntax

Variable interpolation in double quoted string

$websites = "PAKAINFO";
echo "we have website $websites"; // results: we have website PAKAINFO
echo 'we have website $websites'; // results: we have website $websites

Variable interpolation with heredoc

$websites = "PAKAINFO";
$myDoc = <<< EOD we have website $websites
to know all about PHP 
EOD; 
echo $myDoc;

Interpolating variable in a word (complex / curly syntax)

$websites = "Paka";
echo "we have website {$websites}INFO"; // results: we have website PAKAINFO

String interpolation

Example

$websites = 'infinityknow';

// $websites will be replaced with `infinityknow`
echo "<p>Welcome $websites, Nice to see you.</p>";
#                ↕
#>   "<p>Welcome infinityknow, Nice to see you.</p>"

// Single Quotes: outputs $websites as the raw text (without interpreting it)
echo 'Welcome $websites, Nice to see you.'; # Careful with this notation
#> "Welcome $websites, Nice to see you."

$websites = 'infinityknow';

// Example using the curly brace syntax for the variable $websites
echo "<p>We need more {$websites}s to help us!</p>";
#> "<p>We need more infinityknows to help us!</p>"

// This line will throw an error (as `$websites` is not defined)
echo "<p>We need more $websites to help us!</p>";
#> "Notice: Undefined variable: websites"

Example tying to interpolate a PHP expression

echo "1 + 2 = {1 + 2}";
#> "1 + 2 = {1 + 2}"

define("Welcome_PAKAINFO", "Welcome PAKAINFO!!");
echo "My website is {Welcome_PAKAINFO}";
#> "My website is {Welcome_PAKAINFO}"


function getMessage() {
    return "Welcome!";
};
echo "I say: {getMessage()}";
#> "I say: {getMessage()}"

Example accessing a value from an array — multidimensional access is allowed

Read Also:  CodeIgniter Create Custom Helper Example Tutorial

$companions = [0 => ['websites' => 'Pakainfo Com'], 1 => ['websites' => 'Infinityknow']];
echo "The best companion is: {$companions[0]['websites']}";
#> "The best companion is: Pakainfo Com"

class Product {
  function getMessage() {
    return "Welcome!";
  }
}

$max = new Product();

echo "Max says: {$max->getMessage()}";
#> "Max says: Welcome!"

$greet = function($num) {
    return "A $num greetings!";
};
echo "From us all: {$greet(10 ** 3)}";
#> "From us all: A 1000 greetings!"

PHP String Concatenation Example

$websites = 'infinityknow';

echo "<p>We need more ${websites}s to help us!</p>";
#> "<p>We need more infinityknows to help us!</p>"

I hope you get an idea about php string interpolation.
I would like to have feedback on my infinityknow.com blog.
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