console.log输出一个在使用调试器时不同的值

Question

我一直在JavaScript做一个sudoku的解算器。有一种非常奇怪的行为。下面是代码和上下文：

solveSudoku = ()=>{
      let sectionsCopy_ =sectionsCopy

      for(let sect =0; sect< 9; sect++){
        for(let box =0; box <9; box++){
          if(sectionsCopy[sect][box] === ''){
            for(let num=1; num<=9;num++){
              if(this.isPossible(sect,box,num)){
                sectionsCopy[sect][box]=''+num
                this.solveSudoku()
                sectionsCopy[sect][box]=''

              }
            }
            return
          }
        }
      }
      debugger
      console.log(sectionsCopy)

  }

这是在一个类内

sectionsCopy是一个全局变量。

sectionsCopy_仅用于调试(轻松查看全局变量的值)

isPossible()是确定num在该位置是否有效的函数。

组是数独3x3平方的索引

box 是数独中单元框的索引。

问题是：

以数独为例：

​

​

当您单击求解时，sectionsCopy变量将存储：

[
     ["2","6","" ,"4","7","" ,"5","8","1"],
     ["" ,"" ,"3","" ,"" ,"" ,"" ,"" ,"4"],
     ["" ,"1","5","" ,"" ,"8","7","6","3"],
     ["" ,"3","" ,"" ,"" ,"6","" ,"" ,"8"],
     ["4","8","9","" ,"" ,"2","3","1","" ],
     ["" ,"7","" ,"8","3","" ,"" ,"" ,"" ],
     ["6","9","" ,"3","" ,"" ,"" ,"1","" ],
     ["" ,"" ,"8","" ,"9","" ,"5","" ,"" ],
     ["" ,"" ,"7","2","" ,"" ,"" ,"9","6"]
]

当我在没有打开调试器的情况下运行它时，我会得到以下结果：

​

​

如果打开调试器，我会看到以下内容：

​

​

下面是并排的结果，不使用调试器时的结果与使用调试器时的结果：

​

​

我原以为调试器下的行为在没有调试器的情况下是一样的(否则就会像本例一样毫无用处)。

我尝试过console.log(sectionsCopy_)，但我知道数组是不可变的，所以没关系

Answer 1

感谢@epascarello便条。

似乎console.log是在数据被修改的时候输出数据的。

我做的解决办法是

let solution = JSON.parse(JSON.stringify(sections))
console.log(solution)

而不是

console.log(sections)