javascript - 验证输入字段时出现问题。 (js)

Question

我需要 validInput 函数来检查输入的所有输入是否都是数字字符/问题是当第一个 if 语句返回 true 时，该函数似乎跳过输入检查。
例如，如果我为 input1 输入 1，然后为 input2 输入“a”，为 input3 输入 -3，则该函数将返回 true 并显示结果。

https://codepen.io/regnagleppod/pen/NdWLYx

html:

        <label>Starting Number: </label>
        <input id="input1" type="text">
        <br>
        <label>Ending Number: </label>
        <input id="input2" type="text">
        <br>
        <label>Step: </label>
        <input id="input3" type="text">
        <button onclick="return playButton()" id="play">Display Evens</button>

js:

       function playButton(){
            run();
            if (validInput()){
                showResult();
            }  
        };

       function validInput(){
            var x = document.getElementById("input1").value;
            var y = document.getElementById("input2").value;
            var z = document.getElementById("input3").value;
            if((x == "")||(isNaN(x))||(x <= 0)){
                alert("Please enter positive numberic character only.");
                return false;
            }
            if((y == "")||(isNaN(x))||(x <= 0)){
                alert("Please enter positive numberic character only.");
                return false;
            }
            if((z == "")||(isNaN(x))||(x <= 0)){
                alert("Please enter positive numberic character only.");
                return false;
            }                
            return true;    
        };

Answer 1

莫希特是正确的，

将函数更改如下，

function validInput(){
            var x = document.getElementById("startingNum").value;
            var y = document.getElementById("endingNum").value;
            var z = document.getElementById("step").value;
            if((x == "")||(isNaN(x))||(x <= 0)){
                alert("Please enter positive numberic character only.");
                return false;
            }
            if((y == "")||(isNaN(y))||(y <= 0)){
                alert("Please enter positive numberic character only.");
                return false;
            }
            if((z == "")||(isNaN(z))||(z <= 0)){
                alert("Please enter positive numberic character only.");
                return false;
            }                
            return true;    
        };