Question

这是我的代码。我尝试过很多东西，但它没有用。请不要给我一些复杂的代码，因为我只是javascript中的中级程序员。因此，如果可以的话，尽量让事情尽可能简单。感谢所有帮助的人。

function readNumberOfEntries() {
                var entryNumber, numberOfEntries, a;
                do {
                    numberOfEntries = Number(prompt("Enter Value Here"));
                    if (numberOfEntries < 2) {
                        alert("Error: Number is not greater than or equal to 2");
                    }
                } while (numberOfEntries < 2);
                for (entryNumber = 0; entryNumber < numberOfEntries; entryNumber++) {
                    a[entryNumber] = Number(prompt("Enter Value"));
                    a = new Array(numberOfEntries);
                    document.writeln(a);
                }
            }

Answer 1

您的代码的问题在于您在for循环的每次迭代中覆盖数组。这应该可以解决您的问题：

function readNumberOfEntries() {
    var entryNumber, numberOfEntries, a;

    do {
        numberOfEntries = Number(prompt("Enter Value Here"));
        if (numberOfEntries < 2) {
            alert("Error: Number is not greater than or equal to 2");
        }
    } while (numberOfEntries < 2);

    a = new Array(numberOfEntries);  

    for (entryNumber = 0; entryNumber < numberOfEntries; entryNumber++) {
        a[entryNumber] = Number(prompt("Enter Value"));
    }

    document.writeln(a);
}

Answer 2

您应该在分配/添加值之前初始化数组。

      function readNumberOfEntries() {
            var entryNumber, numberOfEntries, a=[];
            do {
                numberOfEntries = Number(prompt("Enter Value Here"));
                if (numberOfEntries < 2) {
                    alert("Error: Number is not greater than or equal to 2");
                }
            } while (numberOfEntries < 2);
            for (entryNumber = 0; entryNumber < numberOfEntries; entryNumber++) {
               // a = new Array(numberOfEntries);
                a[entryNumber] = Number(prompt("Enter Value"));

                document.writeln(a);
            }
        }

如何从提示输入数组？

2 个答案: