非线性参数的函数定义方式

let fun = function ( a, b, c, d) {
    let options = {
        a: 1,
        b: 'a',
        c: {},
        d: function ( a, b, c) {}
    };

    let isUndefined = o => typeof o == 'undefined';
    let isFunction = o => typeof o == 'function';
    let isNumber = o => typeof o == 'number';
    let isString = o => typeof o == 'string';
    let isObject = o => typeof o == 'object';

    let setOptions = function ( o) {
        if ( isNumber( o)) {
            options.a = o;
        } else if ( isString( o)) {
            options.b = o;
        } else if ( isObject( o)) {
            options.c = o;
        } else if ( isFunction( o)) {
            options.d = o;
        }
    }

    for ( let obj of arguments) {
        setOptions( obj);
    }

    options.d( options.a, options.b, options.c);
}

fun( ( a, b, c) => {
    console.log( a, b, c);
}, { list:[]}, 3, 'b');