求问

function first(v) { console.log(v, 'first'); }
function second(v) { console.log(v, 'second'); }
function Third(v) { console.log(v, 'Third'); }
function Fourth(v) { console.log(v, 'Fourth'); }
function Fifth(v) { console.log(v, 'Fifth'); }
function fnTest(value) {
const methods = {
'a': first,
'b': second,
'c': Third,
'd': Fourth,
'e': Fifth
};
methods[value]?.(value);
}
fnTest('a');
fnTest('e');

function first(v) { console.log(v, 'first'); }
function second(v) { console.log(v, 'second'); }
function Third(v) { console.log(v, 'Third'); }
function Fourth(v) { console.log(v, 'Fourth'); }
function Fifth(v) { console.log(v, 'Fifth'); }
function Sixth(v) { console.log(v, 'Sixth'); }
function fnTest(value) {
// new Map() 形式 (可以传不同类型)
const methodMap = new Map([
['a', first],
['b', second],
['c', Third],
['d', Fourth],
['e', Fifth],
[100, Sixth]
]);
methodMap.get(value)?.(value);
}
fnTest(100);
fnTest('js');