javascript - 在 JavaScript 中仅随机选择特定数组

Question

我有多个数组，例如

 array1 = ["car","boot","bike"];
 array2 = ["table","human","cat"];
 array3 = ["boot","pc","iphone"];
 array4 = ["boot","pc","iphone"];
 array5 = ["bike","human","pet"];

这是随机获取数组的代码

  var card;
  var rand;
  var arr = [1,2,3,4,5];
  rand = arr[Math.floor(Math.random() * arr.length)];

 if(rand == 1){ card = array1; }else 
 if(rand == 2){ card = array2; }else 
 if(rand == 3){ card = array3; }else 
 if(rand == 4){ card = array4; }else 
 if(rand == 5){ card = array5; }

如何仅从没有值 "bike" 的数组中进行选择，或者如何仅从数组中第三个位置没有 "bike" 的数组中进行选择数组？

Answer 1

// We want one array containing all the data, so we only have to look at one place.
// Remember, an array can contain anything, including other arrays.
var words = [
    ["car","boot","bike"],
    ["table","human","cat"],
    ["boot","pc","iphone"],
    ["boot","pc","iphone"],
    ["bike","human","pet"]
];

// Let's make a function we can reuse to make things easier
var getArray = function( wordToIgnore ) {
    // we need a random number here, but we also want to filter out any arrays that contain the word we have to ignore.
    // SO we do the filter first, since if affects the random number.
    var arraysToSearch = words.filter(function ( array ) {
        // Standard filter function. We have to return true if the array should stay or false if it has to be removed.
        // So we look at the index of the word we're searching for.
        // If the word exists, we want to remove the array, else keep it.
        return array.indexOf( wordToIgnore ) === -1;

        // To get the 'bike' in 3rd position filter, we just need to update the filter function so it only looks at the 3rd position instead of any index.
        // return array[2] === wordToIgnore;
    });
    // Now that we have the arrays we want to search in, we need a random array of those remaining arrays.
    // If we multiply Math.random() with a number, we directly get the number we need.
    // So with 3 arrays remaining, we want an index between 0 and 2
    var index = Math.floor( Math.random() * (arraysToSearch.length) );
    // Now that we have an index and an array filled with valid arrays, we can just return one;
    return arraysToSearch[ index ];
};

// Let's use our function!
var randomArrayWithoutABike = getArray('bike');