JavaScript一些判斷寫法
阿新 • • 發佈:2018-12-21
例1:if else if else
const fn =(status)=>{
if(status === 1.1){
console.log(1);
}else if(status === 2){
console.log(2.2);
}else if(status === 3){
console.log(3.3);
}else{
console.log(4.4);
}
}
fn(3)
例2:三元運算
const fn = (status) => { let action = status === 1 ? console.log(1.1) : (status === 2 ? console.log(2.2) : (status === 3 ? console.log(3.3) : console.log(4.4))) return action } fn(2)
例3:物件陣列方法
const actions ={
'1':[1,1.1],
'2':[2,2.2],
'3':[3,3.3],
'default':[4,4-4]
}
const fn = (status) => {
let action = actions[status] || actions['default']
console.log(action[0]);
console.log(action[1]);
}
fn(2)
例4:switch case
const fn = status => { switch (status) { case 1: console.log(1.1); break case 2: console.log(2.2); break case 3: console.log(3.3); break } } fn(2)
例5:map
const actions = new Map([ [1,[1.1,1.2]], [2,[2.2,2.3]], [3,[3.3,3.4]], ['default',[4.4,4.5]] ]) const fn = (status) =>{ let action = actions.get(status) || actions.get('default') console.log(action[0]); console.log(action[1]); } fn(2)