# spread operator The spread syntax allows an expression to be expanded in places where multiple arguments (for function calls) or multiple elements (for array literals) or multiple variables (for destructuring assignment) are expected. # steps Copying an object but replacing some properties: > This one we will need bable to make it work ```javascript const myClient = { name : 'John', lastname: 'Doe', city: 'London' } function getNewClient(client, newName) { return { ...client, name: newName } } const myClientB = getNewClient(myClient); console.log(myClientB); ``` We can pass arguments to a function: ```javascript const numbers = [3, 5, 6] ; function sumThreeNumbers(a, b, c) { return a + b + c; } const result = sumThreeNumbers(...numbers) console.log(result); ``` We can concat arrays ```javascript const numbersA = [1, 2, 3]; const numbersB = [4, 5, 6]; const totalNumbers = [...numbersA, ...numbersB, 7, 8] console.log(totalNumbers); ```