一种检查字符串是否包含来自特定 substring 的字符的方法

Question

我正在做一个编码训练营，我们的目标是设置一个密码生成器，用户可以选择哪种类型的字符（小写、大写、数字和特殊字符）和长度，并为他们提供一个随机的安全密码。

除了作业的一个重要部分，即生成的密码必须包含用户选择的每个字符外，我能够使它的所有方面都起作用。 它目前是随机抓取的，因此如果您选择所有 4 个条件，它们将全部出现并不总是保证。 我如何验证这一点？

const lowCaseArr = "abcdefghijklmnopqrstuvwxyz";
const upCaseArr = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const numeralArr = "1234567890";
const specialArr = "!@#$%^&*";

function getLength() {
    while (true) {
        var userLength = parseInt(prompt("How many numbers, between 8 and 128, would you like to use? (Enter 0 to cancel)"));
        if (userLength == 0) {
            return 0;
        } else if (userLength > 128 || userLength < 8) {
            alert("You must enter a number between 8-128.");
        } else if (userLength <= 128 && userLength >= 8) {
            alert("Great! Your have selected a password with " + userLength + " characters.");
            return userLength;
        }
    } 
}

function randChar(passwordCharacters) {
    return passwordCharacters.charAt(Math.floor(Math.random() * passwordCharacters.length));
}

function makePassword(userLength, passwordCharacters) { 
    var securePassword = "";
    for (i = 0; i < userLength; i++) {    
        securePassword += randChar(passwordCharacters);
    }
    return securePassword;
}

function generatePassword() {
    var userLength = getLength();
    if (userLength == 0) {
        return "User Cancelled Request";
    }


    var passwordCharacters = "";
    var askLowerCase = confirm("Would you like to include lower case characters? (a, b, c)");
    if (askLowerCase !== true) {
        alert("Got it. No lower case characters will be included.");
    } else {
        alert("Great! Your password will include lower case characters!");
        passwordCharacters += lowCaseArr;
    }

    var askUpperCase = confirm("Would you like to include upper case characters? (A, B, C)");
    if (askUpperCase !== true) {
        alert("Got it. No upper case characters will be included.");
    } else {
        alert("Great! Your password will include upper case characters!");
        passwordCharacters += upCaseArr;
    }

    var askNumerals = confirm("Would you like to include numeral characters? (1, 2, 3)");
    if (askNumerals !== true) {
        alert("Got it. No numeral characters will be included.");
    } else {
        alert("Great! Your password will include numeral characters!");
        passwordCharacters += numeralArr;
    }

    var askSpecial = confirm("Would you like to include special characters? (~, !, @)");
    if (askSpecial !== true) {
        alert("Got it. No special characters will be included.");
    } else {
        alert("Great! Your password will include special characters!");
        passwordCharacters += specialArr;
    }    

    var basePassword = makePassword(userLength, passwordCharacters);

    var securePassword = validateOptions(basePassword, askLowerCase, askUpperCase, askNumerals, askSpecial);
    return securePassword;

}

var generateBtn = document.querySelector("#generate");

function writePassword() {
    var password = generatePassword();
    var passwordText = document.querySelector("#password");

    passwordText.value = password;
}

generateBtn.addEventListener("click", writePassword);

我的想法是创建一个 function 来验证密码，我只是不确定这里最好的逻辑是什么。

function validateOptions(basePassword, askLowerCase, askUpperCase, askNumerals, askSpecial) {

    var securePassword = basePassword;

    // while (missing requirements) {
    // Validate that all selected characters have been included

    //  if securePassword does not contain lowercase, 
    //      then replace a random char in string with lowercase character
    //  if securePassword does not contain uppercase,
    //      then replace a random char in string with uppercase character
    //  if securePassword does not contain numbers,
    //      then replace a random char in string with numeral character
    //  if securePassword does not contain special characters,
    //      then replace a random char in string with a special character
    //  }
    
    return securePassword;
}

Answer 1

与其在事后更改密码，不如通过确保密码满足所有约束从一开始就正确生成密码。

我已经使用了您的代码片段来生成一个独立的 function makeSecurePassword() ，它接受多个 arguments： userLength 、 askLowerCase 、 askUpperCase 、 askNumerals 、 askSpecial 。 它返回请求的userLength的密码，仅包含请求的字符类型。 它使用您的randChar()助手 function。

var securePassword = makeSecurePassword( 10, true, true, true, true );

console.log(securePassword);

// Return a random character from passwordCharacters:
function randChar(passwordCharacters) {
    return passwordCharacters.charAt(Math.floor(Math.random() * passwordCharacters.length));
}

function makeSecurePassword( userLength, askLowerCase, askUpperCase, askNumerals, askSpecial ) {
    const lowCaseArr = "abcdefghijklmnopqrstuvwxyz";
    const upCaseArr = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    const numeralArr = "1234567890";
    const specialArr = "!@#$%^&*";

    var password = [];

    // Decide which chars to consider:
    charArray = [];
    if ( askLowerCase ) {
        charArray.push( lowCaseArr );
    }
    if ( askUpperCase ) {
        charArray.push( upCaseArr );
    }
    if ( askNumerals ) {
        charArray.push( numeralArr );
    }
    if ( askSpecial ) {
        charArray.push( specialArr );
    }
    
    let x = 0; // index into charArray
    for ( var i=0; i < userLength; i++ ) {
        var a = charArray[x]; // Which array of chars to look at

        // Insert at random spot:       
        password.splice( password.length, 1, randChar( a ) );

        // Pick next set of chars:
        if ( ++x >= charArray.length ) {
            x = 0; // Start with the first set of chars if we went past the end
        }
    }

    return password.join(''); // Create a string from the array of random chars
}