一种检查字符串是否包含来自特定子字符串的字符的方法

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;

    }

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函数makeSecurePassword()，该函数接受多个参数：userLength, askLowerCase, askUpperCase, askNumerals, askSpecial。它返回请求的密码userLength，仅包含请求的字符类型。它使用你的randChar()辅助函数。

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

}