Property key collation in @property

• Atomicity of Nonatomic/atomic

• By default, the method synthesized by the compiler ensures its atomicity (atomicity) through the locking mechanism. If you have a nonatomic trait, you do not use a sync lock.

• Read/write Permissions readwrite/readonly

• Memory Management semantics

• Assign The Set method only operates on simple assignments for the scalar type, cgfloat, or nsinteger, etc.

• Strong "Owning relationship" sets a new value for this property, the set method retains the new value, releases the old value, and then sets the new value up

• Weak When a non-owning relationship sets a new value for this property, the setting method neither preserves the new value nor releases the old value. This trait is similar to assign, but the property is also emptied when the object it refers to is destroyed (nil out)

• unsafe_unretained The semantics of this trait are the same as assign, but it applies to the object type, which expresses a "non-owning relationship" ("not reserved", unretained), when the target object is destroyed , property values are not automatically emptied ("unsafe", unsafe), which differs from weak

• copy of this trait expresses a relationship similar to strong. However, the set method does not retain the new value, but instead copies the copy

• Method Name

• Getter=<name>

• @property (nonatomic, Getter=ison) BOOL on;

• Setter=<name> not very common
  

Property key collation in @property