javascript递归变量问题

我最近使用javascript编写了MinMax算法，但是当我实现递归时

变量的变化似乎很奇怪，下面是代码：

function moveValue(istate, move, moveFor, nextTurn, depth){

    console.log("the original state is: ", istate)
    var state = stateMove(istate, move, nextTurn);
    var winner = status.detectWin(state)
    console.log("now the istate is:", istate)
    console.log("now the state is: ", state)

    if (winner == 'tie'){
        return 0;
    } else if (winner != 0){
        if (moveFor == nextTurn) return 10 - depth;
        else return depth - 10;
    }

    //if the the current operation is not the same with the original, minimum scenario
    //if the the current operation is the same with the original, maximum scenario
    var hope = 999;
    if (moveFor != nextTurn) hope = -999;

    var moves = getLegalMoves(state);

    for (var i=0; i<9; i++){
        if (moves.indexOf(i) > -1) {
            var value = moveValue(state, i, moveFor, -nextTurn,  depth+1);
            if (moveFor == nextTurn && value < hope  ||moveFor != nextTurn && value > hope ){
                hope = value;
            }            

        }
    }

    return hope;

}

stateMove

函数在这里，firstPlayer、secondPlayer与单元格的方式相同

function stateMove(state, move, nextTurn){
    var value = firstPlayer;
    if (nextTurn == -1) value = secondPlayer;
    state[move] = value
    return state
}

---

stateMove

函数正在变异传递给它的数组。将其更改为创建阵列副本将解决此问题：

function stateMove(state, move, nextTurn){
    var nextState = state.slice(0);
    var value = firstPlayer;
    if (nextTurn == -1) value = secondPlayer;
    nextState[move] = value;
    return nextState;
}

---

我怀疑您的

stateMove

函数正在更改

istate

数组，而不是复制它。如果你为这个函数添加代码，它会使问题更容易诊断。嗨，@musicaly\u ut，我添加了它，谢谢你的回答哇，你能解释一下吗？它如何更改参数传递的状态？结束了吗？但这在音乐上太不典型了_ut@user3526776除了原语之外，Javascript几乎是一种通过引用传递的语言。因此，如果更改传递的对象（数组也是对象+细节）的任何属性（请记住，索引值也是属性），则原始值将被更改。这里的解释更加完整：非常感谢！我被困在这里一整天了！谢谢again@user3526776没问题。此外，正是您的调试技能使您的解决方案达到了一英寸的高度。

function stateMove(state, move, nextTurn){
    var value = firstPlayer;
    if (nextTurn == -1) value = secondPlayer;
    state[move] = value
    return state
}

function stateMove(state, move, nextTurn){
    var nextState = state.slice(0);
    var value = firstPlayer;
    if (nextTurn == -1) value = secondPlayer;
    nextState[move] = value;
    return nextState;
}