# Dart – Spread Operator (…)

• Last Updated : 31 Jan, 2022

In Dart, Spread Operator (…) and Null-aware Spread Operator (…?) are used for inserting multiple elements in a collection like Lists, Maps, etc.

Syntaxes:

`...Data_structure`
`...?Data_structure`

Example 1: Using spread operators with List.

## Dart

 `// main function start ` `void` `main() { ` ` `  `   ``// initialise a List l1 ` `   ``List? l1 = [``"Geeks"``,``"For"``,``"Geeks"``]; ` `   `  `  ``// initialize another List l2 using l1 ` `  ``List? l2=[``"Wow"``,...l1,``"is"``,``"amazing"``]; ` ` `  `   ``// print List l2 ` `   ``print(l2); ` `}`

Output :

`[Wow, Geeks, For, Geeks, is, amazing]`

Example 2: Using Spread operator with Map.

## Dart

 `// main function start ` ` `  `void` `main() { ` `   `  `   ``// initialise a Map m1 ` `   ``Map? m1 = {``"name"``:``"John"``,``"age"``:21}; ` `   `  `  ``// initialize another Map m2 using m1 ` `  ``Map? m2={``"roll no"``:45,``"class"``:12,...m1}; ` ` `  `   ``// print Map m2 ` `   ``print(m2); ` `}`

Output :

`{roll no: 45, class: 12, name: John, age: 21}`

Example 3: Using spread operator with Sets.

## Dart

 `// main function start ` `void` `main() { ` `   `  `  ``// first set s1   ` `  ``Set<``int``> s1 = {5, 4, 3}; ` ` `  `  ``// second set s2 ` `  ``Set<``int``> s2 = {3, 2, 1}; ` ` `  `  ``// result Set ` `  ``Set<``int``> result = {...s1, ...s2}; ` ` `  `  ``// print result set ` `  ``print(result); ` `} `

Output:

`{5,4,3,2,1}`

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