Nested ternary operators without explicit parentheses

Nested ternary operations must explicitly use parentheses to dictate the order of the operations. Previously, when used without parentheses, the left-associativity would not result in the expected behaviour in most cases.

Parentheses are not required when nesting into the middle operand, as this is always unambiguous and not affected by associativity:

Array and string offset access using curly braces

The array and string offset access syntax using curly braces is deprecated. Use $var[$idx] instead of $var{$idx}.

(real) cast and is_real() function

The (real) cast is deprecated, use (float) instead.

The is_real() function is also deprecated, use is_float() instead.

Unbinding $this when $this is used

Unbinding $this of a non-static closure that uses $this is deprecated.

parent keyword without parent class

Using parent inside a class without a parent is deprecated, and will throw a compile-time error in the future. Currently an error will only be generated if/when the parent is accessed at run-time.

allow_url_include INI option

The allow_url_include ini directive is deprecated. Enabling it will generate a deprecation notice at startup.

Invalid characters in base conversion functions

Passing invalid characters to base_convert(), bindec(), octdec() and hexdec() will now generate a deprecation notice. The result will still be computed as if the invalid characters did not exist. Leading and trailing whitespace, as well as prefixes of type 0x (depending on base) continue to be allowed.

Using array_key_exists() on objects

Using array_key_exists() on objects is deprecated. Instead either isset() or property_exists() should be used.

Magic quotes functions

The get_magic_quotes_gpc() and get_magic_quotes_runtime() functions are deprecated. They always return false.

hebrevc() function

The hebrevc() function is deprecated. It can be replaced with nl2br(hebrev($str)) or, preferably, the use of Unicode RTL support.

convert_cyr_string() function

The convert_cyr_string() function is deprecated. It can be replaced by one of mb_convert_string(), iconv() or UConverter.

money_format() function

The money_format() function is deprecated. It can be replaced by the intl NumberFormatter functionality.

ezmlm_hash() function

The ezmlm_hash() function is deprecated.

restore_include_path() function

The restore_include_path() function is deprecated. It can be replaced by ini_restore('include_path').

Implode with historical parameter order

Passing parameters to implode() in reverse order is deprecated, use implode($glue, $parts) instead of implode($parts, $glue).