题解 | #实现call#

Function.prototype._call = function(context) {
    context = context || window;
    let args = [];
    context.fn = this;
    for (let i = 1; i < arguments.length; i++) {
        args.push('arguments[' + i + ']');
    }
    let result = eval(`context.fn(${args})`);
    delete context.fn;
    return result;
}