Removing quotes – a step by step example of manipulating array data

This article shows some techniques of manipulating data in an array. To keep it simple, let’s start by looking how we can remove quotes from a variable. To remove a character, we can replace it with nothing using str_replace() function.

$a = "'pineapple'";
$b = '"guava"';
print "$a $b\n";
$a = str_replace("'","",$a);
$b = str_replace('"','',$b);
print "$a $b\n";

This results in:

'pineapple' "guava"
pineapple guava

Consider this code

function remove_single_quotes(&$value) {
    $value = str_replace("'","",$value);
} 
function strip_single_quotes($value) {
    return str_replace("'","",$value);
}
print "original\n";
$fruits = array("'apple'","'banana'","'nectar'");
print_r($fruits);

# does not work
print "Using foreach\n";
foreach ($fruits as $fruit) { $fruit = str_replace("'","",$fruit); }
print_r($fruits);

print "original\n";
$fruits = array("'apple'","'banana'","'nectar'");
print_r($fruits);

print "Using for loop\n";
for ($i = 0; $i < count($fruits); $i++) {
    $fruits[$i] = str_replace("'","",$fruits[$i]);
}
print_r($fruits);

print "original\n";
$fruits = array("'apple'","'banana'","'nectar'");
print_r($fruits);

print "Using for loop by value\n";
for ($i = 0; $i < count($fruits); $i++) {
    $fruits[$i] = strip_single_quotes($fruits[$i]);
}
print_r($fruits);

print "original\n";
$fruits = array("'apple'","'banana'","'nectar'");
print_r($fruits);

print "Using for loop by reference\n";
for ($i = 0; $i < count($fruits); $i++) {
    remove_single_quotes($fruits[$i]);
}
print_r($fruits);

print "original\n";
$fruits = array("'apple'","'banana'","'nectar'");
print_r($fruits);

print "Using array_walk\n";
array_walk($fruits,'remove_single_quotes');
print_r($fruits);

Output:

original
Array
(
   [0] => 'apple'
   [1] => 'banana'
   [2] => 'nectar'
)
Using foreach
Array
(
   [0] => 'apple'
   [1] => 'banana'
   [2] => 'nectar'
)
original
Array 
(
   [0] => 'apple'
   [1] => 'banana'
   [2] => 'nectar'
) 
Using for loop
Array
(
   [0] => apple
   [1] => banana
   [2] => nectar
)
original
Array
(
   [0] => 'apple'
   [1] => 'banana'
   [2] => 'nectar'
)
Using for loop by value
Array
(
   [0] => apple
   [1] => banana
   [2] => nectar
)
original
Array
(
   [0] => 'apple'
   [1] => 'banana'
   [2] => 'nectar'
)
Using for loop by reference
Array
(
   [0] => apple
   [1] => banana
   [2] => nectar
)
original
Array
(
   [0] => 'apple'
   [1] => 'banana'
   [2] => 'nectar'
)
Using array_walk
Array
(
   [0] => apple
   [1] => banana
   [2] => nectar
)