Spread operator

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This operator expands an iterable like an array or a string in every place that can get multiple values

not to get confused with rest parameters

let arr1 = [1,2,3];

let arr2 = [4,5,6];
let combined = [...arr1, ...arr2];
//combined now equals [1,2,3,4,5,6]`}</CodeBlock> <P>It works similarly with objects too</P> <CodeBlock>{`let obj1 = {a: 1, b:2, c:3};
let obj2 = {d: 4, e:5, f:6};
let combined = {...obj1, ...obj2};
//combined now equals {a: 1, b:2, c:3, d: 4, e:5, f:6};`}</CodeBlock> <P>You can use it as function arguments</P> <CodeBlock>{`function greet(day, month, year){
console.log(\`your birthday is: \${month}/\${day}/\${year} !\`);
let birthday = [29,7,1987]
//will print: your birthday is: 7/29/1987 !