下面的代码还将检查PASTE事件。 取消“ruleSetArr_4”的注释，并在“ruleSetArr”中添加(concate)以允许浮点数。 简单的复制/粘贴功能。用参数中的input元素调用它。 例如:inputIntTypeOnly($('输入[name = " inputName "] '))

function inputIntTypeOnly(elm){ elm.on("keydown",function(event){ var e = event || window.event, key = e.keyCode || e.which, ruleSetArr_1 = [8,9,46], // backspace,tab,delete ruleSetArr_2 = [48,49,50,51,52,53,54,55,56,57], // top keyboard num keys ruleSetArr_3 = [96,97,98,99,100,101,102,103,104,105], // side keyboard num keys ruleSetArr_4 = [17,67,86], // Ctrl & V //ruleSetArr_5 = [110,189,190], add this to ruleSetArr to allow float values ruleSetArr = ruleSetArr_1.concat(ruleSetArr_2,ruleSetArr_3,ruleSetArr_4); // merge arrays of keys if(ruleSetArr.indexOf() !== "undefined"){ // check if browser supports indexOf() : IE8 and earlier var retRes = ruleSetArr.indexOf(key); } else { var retRes = $.inArray(key,ruleSetArr); }; if(retRes == -1){ // if returned key not found in array, return false return false; } else if(key == 67 || key == 86){ // account for paste events event.stopPropagation(); }; }).on('paste',function(event){ var $thisObj = $(this), origVal = $thisObj.val(), // orig value newVal = event.originalEvent.clipboardData.getData('Text'); // paste clipboard value if(newVal.replace(/\D+/g, '') == ""){ // if paste value is not a number, insert orig value and ret false $thisObj.val(origVal); return false; } else { $thisObj.val(newVal.replace(/\D+/g, '')); return false; }; }); }; var inptElm = $('input[name="inputName"]'); inputIntTypeOnly(inptElm); <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script> <input type="text" name="inputName" value="1">

在准备验证任何东西时调用此函数。我在这里使用了一个文本框

在我的HTML中:

<input type="button" value="Check IT!" onclick="check(document.getElementById('inputboxToValidate').value);" />

在JavaScript代码中:

function check(num){
    var onlynumbers = true
    for (var i = 0; i < (num.length - 1); i++) {
        if (num.substr(i, 1) != "0" || num.substr(i, 1) != "1" || num.substr(i, 1) != "2" || num.substr(i, 1) != "3" || num.substr(i, 1) != "4" || num.substr(i, 1) != "5" || num.substr(i, 1) != "6" || num.substr(i, 1) != "7" || num.substr(i, 1) != "8" || num.substr(i, 1) != "9") {
            alert("please make sure that only numbers have been entered in the Quantaty box");
            onlynumbers = false
        }
    }
    if (onlynumbers == true) {

        //Execute Code
    }
}

input type="number"是一个HTML5属性。

在另一种情况下，这将帮助你:

function isNumberKey(evt){
    var charCode = (evt.which) ? evt.which : evt.keyCode
    if (charCode > 31 && (charCode < 48 || charCode > 57))
        return false;
    return true;
}

<input type="number" name="somecode" onkeypress="return isNumberKey(event)"/>

HTML5有<input type=number>，这听起来很适合你。目前，只有Opera原生支持它，但有一个项目有一个JavaScript实现。

我找不到一个明确的答案，它不会每次都遍历整个字符串，所以这里:

document.querySelectorAll("input").forEach(input => {
  input.addEventListener("input", e => {
    if (isNaN(Number(input.value[input.value.length-1])) && input.value[input.value.length-1] != '.') {
      input.value = input.value.slice(0, -1);
    }
  })
});

没有正则表达式，它会在每次输入时检查最后一个字符，如果它不是数字或句点，它就会切片。

最好的方法(允许所有类型的数字-实负，实正，iinteger负，整数正)是:

$(input).keypress(function (evt){
    var theEvent = evt || window.event;
    var key = theEvent.keyCode || theEvent.which;
    key = String.fromCharCode( key );
    var regex = /[-\d\.]/; // dowolna liczba (+- ,.) :)
    var objRegex = /^-?\d*[\.]?\d*$/;
    var val = $(evt.target).val();
    if(!regex.test(key) || !objRegex.test(val+key) || 
            !theEvent.keyCode == 46 || !theEvent.keyCode == 8) {
        theEvent.returnValue = false;
        if(theEvent.preventDefault) theEvent.preventDefault();
    };
});