在Node JS脚本中，正在使用公式来生成两个值之间的随机数。这是函数randomIntInc：
function randomIntInc(low, high) {
return Math.floor(Math.random() * (high - low + 1) + low);
}
该函数被调用时具有两个低值和高值：
let randomNumber = randomIntInc(requestedStart, requestedEnd);
console.log(requestedStart)在执行上述行之前会产生542（预期）
console.log(requestedEnd)在执行上述行之前会产生592（预期）
现在，运行上面的行并记录输出会产生任何值，通常在6到50之间。
发生了什么事？在执行随机数之前进行记录会显示正确的范围，但是输出的数字只是不在给定范围内。
这是完整代码（相关代码位于113 ）（请忽略与/模因或复活节彩蛋无关的不良行为代码）：
// Copyright (C) 2018, Julian Lachniet, Jacob Wysko
// Dependencies
var Discord = require('discord.io'),
logger = require('winston'),
auth = require('../auth.json'),
rn = require('random-number'),
http = require('http'),
request = require('request');
// Authorize connection
var bot = new Discord.Client({
token: auth.token,
autorun: true
});
// GOOGLE SHEETS API
const fs = require('fs');
const readline = require('readline');
const {google} = require('googleapis');
const SCOPES = ['https://www.googleapis.com/auth/spreadsheets.readonly'];
const TOKEN_PATH = 'credentials.json';
// If bot disconnects, try to reconnect
bot.on('disconnect', function(msg, code) {
if (code === 0) return console.error(msg);
bot.connect();
});
// Returns the current timestamp
function timeStamp() {
return "[" + new Date().toString().split(" G")[0] + "]";
}
// Returns a random integer
function randomIntInc(low, high) {
return Math.floor(Math.random() * (high - low + 1) + low);
}
// When a message is recieved
bot.on('message', function(user, userID, channelID, message, evt) {
let valid = false;
// Log what the user sent (verifies it wasn't sent by the bot)
if (user !== 'teacher-quotes-bot') {
console.log(timeStamp() + " " + user + ": " + message);
}
// Sends a message with text "message", logs it
function sendMessage(message) {
bot.sendMessage({
to: channelID,
message: message
});
console.log(timeStamp() + " Bot: " + message);
valid = true;
}
// Sends a message based on a list of commands
function infoMessage(commands, response) {
if (commands.includes(input)) {
sendMessage(response);
}
validCommands.push(commands);
}
// If the message began with a '!' (e.g., !cmd)
if (message.substring(0, 1) === '!') {
var args = message.substring(1).split(' ');
var input = args[0];
var validCommands = [];
// Commands
infoMessage(['accuracy', 'disclaimer', 'terms'], '<#440534402171404289>');
infoMessage(['android', 'app'], 'https://play.google.com/store/apps/details?id=com.jacobwysko.teacherquotes');
infoMessage(['format', 'formats', 'formatting'], '"Quote text." - Teacher, MM/DD/YYYY');
infoMessage(['code', 'git', 'github', 'roadmap', 'trello', 'source', 'sourcecode'], 'https://github.com/wyskoj/TeacherQuotesVersion3\nhttps://github.com/jlachniet/TeacherQuotesBot');
infoMessage(['faq', 'help', '?'], "You've been <#440504422028804107>ed.");
infoMessage(['ping', 'pong'], 'Pong!');
infoMessage(['rule', 'rules'], "You've been <#440500062011916298>ed");
infoMessage(['apple', 'ios', 'web', 'website'], 'http://jacobwysko.com/teacherquotes');
infoMessage(['cmd', 'cmds', 'command', 'commands'], 'Valid Commands:\n - accuracy\n - app\n - format\n - github\n - help\n - ping\n - rules\n - website');
// Easter eggs
infoMessage(['ivefallenandicantgetup'], 'Stay right there, ' + user + "! Don't worry, help is on the way!");
infoMessage(['goddammitimpregnant'], '...for the fifteenth damn time!');
infoMessage(['yeah'], 'ｂｏｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉｉ');
infoMessage(['ohhi'], 'mark');
infoMessage(['poopity'], 'scoop');
switch (input) {
case 'fact':
case 'randomfact':
// Sends a random fact
request('https://spreadsheets.google.com/feeds/list/1ggvma51cj7ryPqfxGv47ZPLuP72keZmFbGE-KBHqbuU/4/public/values?alt=json', function(error, response, body) {
let boi = body;
let output = JSON.parse(boi);
let options = {
min: 0,
max: 11,
integer: true
};
let randomNumber = rn(options);
sendMessage(output["feed"]["entry"][randomNumber]["gsx$randomfact"]["$t"]);
});
break;
case 'randomquote':
// Sends a random quote
if (args.length !== 2) {
request('https://spreadsheets.google.com/feeds/list/1ggvma51cj7ryPqfxGv47ZPLuP72keZmFbGE-KBHqbuU/1/public/values?alt=json', function(error, response, body) {
let output = JSON.parse(body);
let options = {
min: 0,
max: output["feed"]["entry"].length,
integer: true
};
let randomNumber = rn(options);
sendMessage(('"' + output["feed"]["entry"][randomNumber]["gsx$quote"]["$t"] + '" - ' + output["feed"]["entry"][randomNumber]["gsx$teacherquoted"]["$t"] + ", " + output["feed"]["entry"][randomNumber]["gsx$date"]["$t"]))
});
} else {
console.log("SPECIFICS TEACHER");
let requestedTeacher = args[1];
request('https://spreadsheets.google.com/feeds/list/1ggvma51cj7ryPqfxGv47ZPLuP72keZmFbGE-KBHqbuU/1/public/values?alt=json', function (error, response, body) {
let quotes = JSON.parse(body);
console.log(quotes);
request('https://spreadsheets.google.com/feeds/list/1ggvma51cj7ryPqfxGv47ZPLuP72keZmFbGE-KBHqbuU/2/public/values?alt=json', function (error, response, body){
let ranges = JSON.parse(body);
console.log(ranges);
let teachers = [];
for (i = 0; i < ranges["feed"]["entry"].length; i++){
teachers.push(ranges["feed"]["entry"][i]["gsx$teacher"]["$t"]);
}
let teacherStart = [];
for (i = 0; i < ranges["feed"]["entry"].length; i++){
teacherStart.push(ranges["feed"]["entry"][i]["gsx$rangestart"]["$t"]);
}
let teacherEnd = [];
for (i = 0; i < ranges["feed"]["entry"].length; i++){
teacherEnd.push(ranges["feed"]["entry"][i]["gsx$rangeend"]["$t"]);
}
let requestedTeacherId = teachers.indexOf(requestedTeacher);
let requestedStart = teacherStart[requestedTeacherId];
let requestedEnd = teacherEnd[requestedTeacherId];
console.log(requestedStart);
console.log(requestedEnd);
let randomNumber = randomIntInc(requestedStart, requestedEnd);
console.log(requestedTeacher);
console.log(randomNumber);
});
});
}
break;
}
if (!valid && !['fact', 'randomfact', 'randomquote'].includes(input)) {
sendMessage('Invalid command. Type "!command" for a list of commands.');
}
} else
if (user !== 'teacher-quotes-bot' && channelID === '465330717782441986') {
let validQuoteRegex = /".+"\s-\s\w+,\s\d{2}\/\d{2}\/\d{4}/;
if (validQuoteRegex.test(message)) { // If the message sent was a valid quote
let justMessage = message.split('"')[1];
let justTeacher = message.split('"')[2].substring(3, message.split('"')[2].length - 12);
let justDate = message.substring(message.length - 10, message.length);
if (justTeacher.indexOf("(") > -1) {
justTeacher = justTeacher.substring(0, justTeacher.indexOf("("));
}
sendMessage("Message: " + justMessage + "\nTeacher: " + justTeacher + "\nDate: " + justDate);
} else {
sendMessage("Invalid Quote");
}
}
});
答案 0 :(得分：3)
似乎返回的JSON将分配给requestedStart和requestedEnd的值存储为字符串而不是数字。在这种情况下，您需要先将它们转换为数字，然后再对随机数范围进行算术运算。
function randomIntInc(low, high) {
console.log({
low,
high,
'(high - low) + 1': (high - low) + 1,
'(high - low + 1) + low': (high - low + 1) + low
});
return Math.floor(Math.random() * (high - low + 1) + low);
}
console.log({
strings: randomIntInc('10', '20'),
numbers: randomIntInc(10, 20)
});
逐步执行字符串调用'10'和'20'会导致以下操作：
('20' - '10' + 1)：运算顺序将导致首先执行减法运算，这将自动将两个字符串都转换为数字并得出10。最后的加法将简单地将两个数字相加并产生11。