嵌套循环中数组2d中的javascript变量丢失

javascript variable in array 2d in nested loop is missing

本文关键字：变量 javascript 中的 数组 2d 嵌套循环      更新时间：2024-02-27

我创建动态表，然后存储值。但我发现最后的数组是错误的。我想找个人帮忙，扩大问题的范围。为什么循环之前x中的x=[[]]而不是[["111"，"0"，"0]]。

x = [];
$(document).on('click', '#save', function(event) {
    x.length = 0;
    var y = [];
    for (var m = 0; m < row; m++) {
      y.length = 0;
      console.log('x before loop = ',x);
      for (var n = 0; n < arr_stklist.length - 1; n++) {
        if (arr_stklist[n] == "text") {
          y.push(document.getElementById('arr_TextAns['+m+']['+n+']').value);
        } else if (arr_stklist[n] == "level") {
          y.push(document.getElementById('arr_LevelAns['+m+']['+n+']').value);
        } 
      }
      // console.log('y = ',y);
      // console.log('x before = ',x);
      x.push(y);
      // console.log('x after = ',x);
    }
    // console.log('final = ',x);
    event.preventDefault(); });

结果是

x before loop = []
y = ["111", "0", "0"]
x before = []
x after = [["111", "0", "0"]]
x before loop = [[]]
y = ["222", "0", "0"]
x before = [["222", "0", "0"]]
x after = [["222", "0", "0"], ["222", "0", "0"]]
final = [["222", "0", "0"], ["222", "0", "0"]]

我想要最后一个是[["111", "0", "0"], ["222", "0", "0"]]

您一直在将相同的数组推送到x上。x.push(y)不复制数组，它只是推送对数组的引用。与其用y.length = 0清空数组，不如用y = []分配一个新数组。

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