前端学习笔记202309学习笔记第九十一天-回调之6

function calculate(a, b, type,callback) {
    let res = 0;
    let sign = '+';
    switch (type) {
        case 'PLUS':
            res = a + b;
            sign = '+'
            break
        case 'MINUS':
            res = a - b;
            sign = '-'
            break
        case 'MUL':
            res = a * b;
            sign = '*'
            break
        case 'DIV':
            res = a / b;
            sign = '/'
            break
        default:
            res = a + b;
            sign = '+'
            break
    }
    callback&&callback(a,b,sign,res)
    return {
        a, b, sign, res
    }
}
// const {a,b,sign,res}=calculate(1,2,'DIV')
// console.log(`${a}${b}${sign}${res}`)
calculate(1,2,'DIV',(a,b,sign,res)=>{
    console.log(`${a}${b}${sign}${res}`)
})

运行结果