优化这段代码： if (state.form.region && state.form.region.length !== 0) { state.form.region.forEach((item: any) => { lastCode = item }) }

== 'east') {
state.form.region = 'west';
}

把上面的代码改为：
if (state.form.region == 'east') {
state.form.region = 'east';
} else {
state.form.region = 'west';
}