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This article mainly introduces the relevant knowledge of "what is the concept of Zval in PHP". The editor shows you the operation process through an actual case. The operation method is simple, fast and practical. I hope this article "what is the concept of Zval in PHP" can help you solve the problem.

1. Concept

Zval is another important data structure in zend, which is used to identify and implement PHP variables. Contains information about the values and types of variables in PHP.

2. Composition

Type: specifies the type described by the variable (integers, strings, arrays, etc.)

Refcount&is_ref: used to implement reference counting (more on later)

Value: the core part, which stores the actual data of the variable

3. Examples

Struct _ zval_struct {union {zend_long lval; / * long value * / double dval; / * double value * / zend_refcounted * counted; zend_string * str; zend_array * arr; zend_object * obj; zend_resource * res Zend_reference * ref; zend_ast_ref * ast; zval * zv; void * ptr; zend_class_entry * ce; zend_function * func; struct {uint32_t w1; uint32_t w2;} ww;} value Union {struct {ZEND_ENDIAN_LOHI_4 (zend_uchar type, / * active type * / zend_uchar type_flags, zend_uchar const_flags, zend_uchar reserved) / * call info for EX (This) * /} v; uint32_t type_info } U1; union {uint32_t var_flags; uint32_t next; / * hash collision chain * / uint32_t cache_slot; / * literal cache slot * / uint32_t lineno; / * line number (for ast nodes) * / uint32_t num_args / * arguments number for EX (This) * / uint32_t fe_pos; / * foreach position * / uint32_t fe_iter_idx; / * foreach iterator index * /} U2;}; this is the end of the introduction of "what is the concept of Zval in PHP". Thank you for reading. If you want to know more about the industry, you can follow the industry information channel. The editor will update different knowledge points for you every day.

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