. in function param
. in for in loops @example :for (let {..., ...} in obj) {}
. array combine. @example : []
function argument
. function a (a, ....b) { }
. a(...[])
. in function param
. in for in loops @example :for (let {..., ...} in obj) {}
. array combine. @example : []
. function a (a, ....b) { }
. a(...[])