Javascript 条件问题答案

【问题标题】：Javascript Conditions ProblemsJavascript 条件问题
【发布时间】：2020-03-21 06:48:09
【问题描述】：

如果用户在 numbers 数组中输入非数字或输入数字“0”，如何添加向用户报告的条件语句？

这是用于 Javascript 的。

这是我的代码。对不起，如果它太多了。

   var numbers = []; // array for storing numbers
            var multNumbers = []; //array for storing multiplied numbers
            var divNumbers = []; //array for storing divided numbers
            var arrayText = ""; // variable for generating a list of numbers to display
            var 
            //function to generate a list of all items in an array with spaces
            function displayList(value, index, array) {
                    arrayText = arrayText + value + " "; 
            }

            //function to enter a number into the numbers array and display the results
            function enterNumber(){
                var input = Number(document.getElementById("inputField").value);
                numbers.push(input);
                arrayText = "";
                numbers.forEach(displayList);
                document.getElementById("displayNumbers").innerHTML = arrayText;
                document.getElementById("inputField").value ="";
            }

            //function to create the array multNumbers and display the results
            function createMult(){
                for (var i=1; i<numbers.length; i++){
                    var product = numbers[i-1] * numbers[i];
                    multNumbers.push(product);
                }
                arrayText = "";
                multNumbers.forEach(displayList);
                document.getElementById("displayMult").innerHTML = arrayText;
            }

            //function to create the array divNumbers and display the results
            function createDiv() {
                var i=1;
                while (i<numbers.length){
                    var dividend = numbers[i-1] / numbers[i];
                    divNumbers.push(dividend);
                    i++;
                }
                arrayText = "";
                divNumbers.forEach(displayList);
                document.getElementById("displayDiv").innerHTML = arrayText;
            }
        ```

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标签： javascript arrays conditional-statements

【解决方案1】：

您可以使用 Number.parseInt 来检查转换是否成功。您可以执行以下操作来检查用户是否输入了数字

//function to enter a number into the numbers array and display the results
function enterNumber(){
    if not (Number.parseInt(document.getElementById("inputField").value)) {
        // use your html to convey the input must be numeric
    }
    else {
        var input = Number(document.getElementById("inputField").value);
        if (input = 0) {
            // use your html to convey the input must be non-zero
        }       
        else {
            numbers.push(input);
            arrayText = "";
            numbers.forEach(displayList);
            document.getElementById("displayNumbers").innerHTML = arrayText;
            document.getElementById("inputField").value ="";        
        }

    }

}

【讨论】：