JavaScript function or parameter

[KISHOR 1988]

[CODE lang="javascript" highlight="3"]const timeFuncRuntime = funcParameter => {
let t1 = Date.now();
funcParameter();
let t2 = Date.now();
return t2 - t1;
}

const addOneToOne = () => 1 + 1;

timeFuncRuntime(addOneToOne);[/CODE]

why is ritten line 3 " funcParameter(); " in block code of function?/ is line3 parameter ?? why is it return with parentheses , though it is parameter???

 

[KISHOR 1988]

[CODE lang="javascript" highlight="3"]const timeFuncRuntime = funcParameter => {
let t1 = Date.now();
funcParameter();
let t2 = Date.now();
return t2 - t1;
}

const addOneToOne = () => 1 + 1;

timeFuncRuntime(addOneToOne);[/CODE]

why is ritten line 3 " funcParameter(); " in block code of function?/ is line3 parameter ?? why is it return with parentheses , though it is parameter???

ritten = *written
return = *written