JS调用函数，所有可能的参数都已排列

JS call function with all possible arguments permuted

本文关键字：参数 排列 有可能 调用 函数 JS      更新时间：2023-09-26

考虑以下数组：

var array1 = [true, false];
var array2 = [1, 2];
var array3 = ["a", "b", "c"];

我想用所有参数组合调用函数myFunc(arg1, arg2, arg3)。但我想避免"foreach"地狱。

有没有可能写函数允许我这样做，所以我可以称之为

cartesianCall(array1, array2, array3, myFunc);

理想情况下使用可变数组计数（myFunc参数）？

编辑：因此函数将被调用：

myFunc(true, 1, "a");
myFunc(true, 1, "b");
myFunc(true, 1, "c");
myFunc(true, 2, "a");
myFunc(true, 2, "b");
myFunc(true, 2, "c");
myFunc(false, 1, "a");
myFunc(false, 1, "b");
myFunc(false, 1, "c");
myFunc(false, 2, "a");
myFunc(false, 2, "b");
myFunc(false, 2, "c");

声明不带参数的函数并使用arguments关键字：

function cartesianCall() {
  for (var i = 0; i < arguments.length; i++) {
     // do something with arguments[i]
  }
}

http://jsfiddle.net/trevordixon/zEqKy/

function cartesianCall(func, args) {
    var combos = allCombos.apply(this, args);
    for (var i = 0; i < combos.length; i++) {
        func.apply(null, combos[i]);
    }
}
function allCombos(first) {
    var isArray = toString.call(first) === "[object Array]";
    if (!isArray) first = [first]; // Convert non-array to an array with the value
                                   // as the only element
    else if (first.length === 0) first = [undefined]; // Convert empty array to an
                                                      // array with undefined as
                                                      // the only element
    if (arguments.length === 1) return first; // base case for recursion
    var result = [],
        rest = allCombos.apply(this, Array.prototype.slice.call(arguments, 1));
    for (var i = 0; i < first.length; i++) {
        for (var j = 0; j < rest.length; j++) {
            result.push([first[i]].concat(rest[j]));
        }
    }
    return result;
}

然后这样使用：

function printArgs() { console.log('Called with arguments:', arguments); }
cartesianCall(printArgs, [
    [true, false],
    undefined,
    [1, 2],
    [],
    'a string',
    ['a', 'b', 'c']
]);

打印：

Called with arguments: [true, undefined, 1, undefined, "a string", "a"] 
Called with arguments: [true, undefined, 1, undefined, "a string", "b"] 
Called with arguments: [true, undefined, 1, undefined, "a string", "c"] 
Called with arguments: [true, undefined, 2, undefined, "a string", "a"] 
Called with arguments: [true, undefined, 2, undefined, "a string", "b"] 
Called with arguments: [true, undefined, 2, undefined, "a string", "c"] 
Called with arguments: [false, undefined, 1, undefined, "a string", "a"] 
Called with arguments: [false, undefined, 1, undefined, "a string", "b"] 
Called with arguments: [false, undefined, 1, undefined, "a string", "c"] 
Called with arguments: [false, undefined, 2, undefined, "a string", "a"] 
Called with arguments: [false, undefined, 2, undefined, "a string", "b"] 
Called with arguments: [false, undefined, 2, undefined, "a string", "c"]

请注意，空数组的处理方式与undefined相同。

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