| Types of | significance | Definition method | System storage location | Scope of use | note |
|---|---|---|---|---|---|
| Static Variable | The system statically allocates the program before the program is executed (that is, the allocation is not changed at runtime) | Variables declared with staic storage class | No initial value assigned is stored in the .bss section, and initial value assigned is stored in the .data section | Both inside and outside the function | The value will be memorized |
| Global variable | Variables defined externally | Defined externally (extern can be added or not) | No initial value assigned is stored in the .bss section, and initial value assigned is stored in the ro.data section | Outside the function, you can use extern to modify | The number of functions can be used internally and externally |
| Automatic variable (local variable) | Local scope variable | Variables defined in the function default to auto declaration | Stack area | Available inside the function | - |
| constant | Unchanged amount | const, define modification | const-modified global variables and define definitions send constants in the constant area (ro.data section); const-modified local variables are in the stack area | - | Value cannot be modified |
const, static variable storage location
D:\OMOstepthree\holiday promotion\test