﻿ Array Operators

# Array Operators

### Table 6.8. Array Operators

ExampleNameResult
\$a + \$bUnionUnion of \$a and \$b.
\$a == \$bEquality`TRUE` if \$a and \$b have the same key/value pairs.
\$a === \$bIdentity`TRUE` if \$a and \$b have the same key/value pairs in the same order and of the same types.
\$a != \$bInequality`TRUE` if \$a is not equal to \$b.
\$a <> \$bInequality`TRUE` if \$a is not equal to \$b.
\$a !== \$bNon-identity`TRUE` if \$a is not identical to \$b.

The `+` operator appends elements of remaining keys from the right handed array to the left handed, whereas duplicated keys are NOT overwritten.

```<?php \$a = array("a" => "apple", "b" => "banana"); \$b = array("a" => "pear", "b" => "strawberry", "c" => "cherry"); \$c = \$a + \$b; // Union of \$a and \$b echo "Union of \\$a and \\$b: \n"; var_dump(\$c); \$c = \$b + \$a; // Union of \$b and \$a echo "Union of \\$b and \\$a: \n"; var_dump(\$c); ?>```

When executed, this script will print the following:

```Union of \$a and \$b: array(3) {  ["a"]=>  string(5) "apple"  ["b"]=>  string(6) "banana"  ["c"]=>  string(6) "cherry" } Union of \$b and \$a: array(3) {  ["a"]=>  string(4) "pear"  ["b"]=>  string(10) "strawberry"  ["c"]=>  string(6) "cherry" } ?>```

Elements of arrays are equal for the comparison if they have the same key and value.

### Example 6.7. Comparing arrays

```<?php \$a = array("apple", "banana"); \$b = array(1 => "banana", "0" => "apple"); var_dump(\$a == \$b); // bool(true) var_dump(\$a === \$b); // bool(false) ?>```

See also the manual sections on the Array type and Array functions.

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