psalm/docs/running_psalm/issues/MixedOperand.md

# MixedOperand

Emitted when Psalm cannot infer a type for an operand in any calculated expression

```php
<?php

echo $GLOBALS['foo'] + "hello";
```

## Why it’s bad

Mixed operands can have fatal consequences, e.g. here:

```php
<?php

function foo(mixed $m) {
    echo $m . 'bar';
}

class A {}

foo(new A()); // triggers fatal error
```
-												Move issues to separate pages

											
										
										
											2020-03-19 17:32:49 +01:00
+								# MixedOperand
 								Emitted when Psalm cannot infer a type for an operand in any calculated expression
 								```php
-												Add opening PHP tags to examples

											
										
										
											2020-03-21 00:13:46 +01:00
+								<?php
-												fix tests

											
										
										
											2022-09-10 13:06:17 +02:00
+								echo $GLOBALS['foo'] + "hello";
-												Move issues to separate pages

											
										
										
											2020-03-19 17:32:49 +01:00
+								```
-												Update MixedOperand.md
											
										
										
											2020-11-08 20:41:08 +01:00
 								## Why it’s bad
 								Mixed operands can have fatal consequences, e.g. here:
 								```php
 								<?php
 								function foo(mixed $m) {
 								    echo $m . 'bar';
 								}
 								class A {}
 								foo(new A()); // triggers fatal error
 								```