Are Set Iterators Mutable or Immutable?Klaus Kreft
The C++ Standard mandates that containers such as std::set provide both mutable and immutable iterators. Unfortunately, mutable iterators turn out to be dangerous when used with sets. If you use one to modify an ele...
比如api接口返回一个set,不期望调用方不小心去修改了返回结果,破坏结果集,这个时候immutable就派上用场了。另外immutable在多线程并发的时候比较提倡,这样可以减少错误率。至于mutable的,函数式编程里头不建议用。 有用 回复 撰写回答 你尚未登录,登录后可以 和开发者交流问题的细节 关注并接收问题和回答的更新提醒 ...
import scala.collection.immutable //mutable:可变 //import scala.collection.mutable object Test11 { //Set:元素不重复 去重: def main(args: Array[String]): Unit = { //格式 // val set1=Set [Int]() // // 省略类型 // val set2=Set (1,2,3,1,2) ...
following types: Bool, Int, Int8, Int16, Int32, Int64, Float, Double, String, Data, Date, Decimal128, and ObjectId (and their optional versions) Unlike Swift’s native collections, MutableSets are reference types, and are only immutable if the Realm that manages them is opened as read...
* * Is pure, i.e. it must always return the same value for the same pair * of values. * * <!-- runkit:activate --> * ```js * const { Map } = require('immutable') * Map({ "c": 3, "a": 1, "b": 2 }).sort((a, b) => { * if (a < b) { return -1; } ...
//scala.collection中的集合要么是mutalbe的,要么是immutable的 //同时该包中也定义了immutable及mutable集合的接口 A collection in package scala.collection can be either mutable or immutable. For instance, collection.IndexedSeq[T] is a superclass of both collection.immutable.IndexedSeq[T] and collection...
Gets the object that is used to obtain hash codes for the keys and to check the equality of values in the immutable hash set.Methods Proširi tablicu Add(T) Adds the specified element to the hash set. Clear() Retrieves an empty immutable hash set that has the same sorting and ord...
When you add or remove elements from an immutable set, a copy of the original set is created with these elements added or removed, and the original set is unchanged. Fields Expand table Empty Gets an immutable hash set for this type that uses the default IEqualityComparer<T>. Properties...
1.ImmutableSet.copyOfreturns an immutable empty set if the specified set is empty. 1 2 Set<String>mutableSet=Sets.newHashSet(); ImmutableSet<String>immutableSet=ImmutableSet.copyOf(mutableSet); The method will throw aNullPointerExceptionif the specified set is null, and any changes in the u...