Set 是Dart编程中的一种特殊类型的集合。其中任何对象只能出现一次。如果我们在集合中执行添加操作,如果对象已经在集合中,则不会添加,否则将添加到集合中。 dart: 核心库提供了 Set 类来实现。
Syntax: Identifier = new Set()
or
Identifier = new Set.from(Iterable)
Here, Iterable is the list of value which will be added in the set .
示例 1:
Dart
void main() {
// create a new set number
Set number = new Set();
// add in the set
number.add(1);
number.add(2);
number.add(5);
number.add(1);
// all elements are retrieved
// in the order in which
// they are inserted
for(var no in number) {
print(no);
}
}
Dart
void main() {
// Create a Set Number Which
// contains a list of value
Set number = new Set.from([1,11,14,11]);
// all elements are retrieved
// in the order in which
// they are inserted
for(var n in number) {
print(n);
}
}
Dart
void main() {
// Create a Set Number Which
// contains a list of value
Set number = new Set.from(['geeks','for','geeks']);
// all elements are retrieved
// in the order in which
// they are inserted
for(var n in number) {
print(n);
}
}
输出:
1
2
5
示例 2:
Dart
void main() {
// Create a Set Number Which
// contains a list of value
Set number = new Set.from([1,11,14,11]);
// all elements are retrieved
// in the order in which
// they are inserted
for(var n in number) {
print(n);
}
}
输出:
1
11
14
示例 3:
Dart
void main() {
// Create a Set Number Which
// contains a list of value
Set number = new Set.from(['geeks','for','geeks']);
// all elements are retrieved
// in the order in which
// they are inserted
for(var n in number) {
print(n);
}
}
输出:
geeks
for