javascript - 邮政编码验证

Question

我需要验证我的表格的一部分，它是基于马来西亚邮政编码的邮政编码，这是一个 5 位数字邮政编码。如何验证用户输入的值只有 5 个数字，不多也不少？提前致谢！

这是我的部分代码：

HTML：

<label>Postcode: <input type="text" name="postcode" id="postcode" required="required"></label><br />

Javascript：

function chkPostcode () {
    var postcode = document.getElementById("postcode").value;
    var pattern = /^[0-9]+$/; //check only alpha characters or space
    var postcodeOK = true;
    
    if ((postcode.length < 5 && postcode.length > 5)){ //same as owner==""
        gErrorMsg = gErrorMsg + "Please enter postcode.\n"
        postcodeOK = false; //if condition or clause complex more readable if branches on separate lines
    }
    else{
        if (!pattern.test(postcode)){
        gErrorMsg = gErrorMsg + "Postcode must only contain numbers.\n"
        postcodeOK = false; //if condition or clause complex more readable if branches on separate lines
        }
    }
//if (!nameOk){
// document.getElementById("owner").style.borderColor = "red";
//
    return postcodeOK;
}

标签： javascripthtml

Answer 1

对于您要完成的工作，这是一个更短的代码。

document.getElementById("postcode").addEventListener("input", function(e) {
  if ( /^\d{5}$/.test(e.target.value)){
    console.log("valid");
    return;
  }
  console.log("invalid");
})

<label>Postcode: <input type="text" name="postcode" id="postcode" required="required"></label><br />