我的最终目标是验证输入字段。输入可以是字母也可以是数字。
当前回答
你也可以试试lodash:
const isNumeric = number =>
_.isFinite(_.parseInt(number)) && !_.isNaN(_.parseInt(number))
其他回答
如果我没记错的话,这个问题需要“contains number”,而不是“is number”。所以:
function hasNumber(myString) {
return /\d/.test(myString);
}
检查它的一种方法是遍历字符串并在命中数字时返回true(或false,这取决于您想要什么)。
function checkStringForNumbers(input){
let str = String(input);
for( let i = 0; i < str.length; i++){
console.log(str.charAt(i));
if(!isNaN(str.charAt(i))){ //if the string is a number, do the following
return true;
}
}
}
无论如何,它都不是刀枪不入的,但它对我来说是有效的,也许它会帮助到别人。
var value = $('input').val();
if(parseInt(value)) {
console.log(value+" is a number.");
}
else {
console.log(value+" is NaN.");
}
Using Regular Expressions with JavaScript. A regular expression is a special text string for describing a search pattern, which is written in the form of /pattern/modifiers where "pattern" is the regular expression itself, and "modifiers" are a series of characters indicating various options. The character class is the most basic regex concept after a literal match. It makes one small sequence of characters match a larger set of characters. For example, [A-Z] could stand for the upper case alphabet, and \d could mean any digit.
从下面的例子
contains_alphaNumeric«它检查字符串是否包含字母或数字(或)字母和数字。连字符(-)将被忽略。 它检查字符串是否只包含任意序列顺序的字母和数字。
例子:
function matchExpression( str ) {
var rgularExp = {
contains_alphaNumeric : /^(?!-)(?!.*-)[A-Za-z0-9-]+(?<!-)$/,
containsNumber : /\d+/,
containsAlphabet : /[a-zA-Z]/,
onlyLetters : /^[A-Za-z]+$/,
onlyNumbers : /^[0-9]+$/,
onlyMixOfAlphaNumeric : /^([0-9]+[a-zA-Z]+|[a-zA-Z]+[0-9]+)[0-9a-zA-Z]*$/
}
var expMatch = {};
expMatch.containsNumber = rgularExp.containsNumber.test(str);
expMatch.containsAlphabet = rgularExp.containsAlphabet.test(str);
expMatch.alphaNumeric = rgularExp.contains_alphaNumeric.test(str);
expMatch.onlyNumbers = rgularExp.onlyNumbers.test(str);
expMatch.onlyLetters = rgularExp.onlyLetters.test(str);
expMatch.mixOfAlphaNumeric = rgularExp.onlyMixOfAlphaNumeric.test(str);
return expMatch;
}
// HTML Element attribute's[id, name] with dynamic values.
var id1 = "Yash", id2="777", id3= "Yash777", id4= "Yash777Image4"
id11= "image5.64", id22= "55-5.6", id33= "image_Yash", id44= "image-Yash"
id12= "_-.";
console.log( "Only Letters:\n ", matchExpression(id1) );
console.log( "Only Numbers:\n ", matchExpression(id2) );
console.log( "Only Mix of Letters and Numbers:\n ", matchExpression(id3) );
console.log( "Only Mix of Letters and Numbers:\n ", matchExpression(id4) );
console.log( "Mixed with Special symbols" );
console.log( "Letters and Numbers :\n ", matchExpression(id11) );
console.log( "Numbers [-]:\n ", matchExpression(id22) );
console.log( "Letters :\n ", matchExpression(id33) );
console.log( "Letters [-]:\n ", matchExpression(id44) );
console.log( "Only Special symbols :\n ", matchExpression(id12) );
把:
Only Letters:
{containsNumber: false, containsAlphabet: true, alphaNumeric: true, onlyNumbers: false, onlyLetters: true, mixOfAlphaNumeric: false}
Only Numbers:
{containsNumber: true, containsAlphabet: false, alphaNumeric: true, onlyNumbers: true, onlyLetters: false, mixOfAlphaNumeric: false}
Only Mix of Letters and Numbers:
{containsNumber: true, containsAlphabet: true, alphaNumeric: true, onlyNumbers: false, onlyLetters: false, mixOfAlphaNumeric: true}
Only Mix of Letters and Numbers:
{containsNumber: true, containsAlphabet: true, alphaNumeric: true, onlyNumbers: false, onlyLetters: false, mixOfAlphaNumeric: true}
Mixed with Special symbols
Letters and Numbers :
{containsNumber: true, containsAlphabet: true, alphaNumeric: false, onlyNumbers: false, onlyLetters: false, mixOfAlphaNumeric: false}
Numbers [-]:
{containsNumber: true, containsAlphabet: false, alphaNumeric: false, onlyNumbers: false, onlyLetters: false, mixOfAlphaNumeric: false}
Letters :
{containsNumber: false, containsAlphabet: true, alphaNumeric: false, onlyNumbers: false, onlyLetters: false, mixOfAlphaNumeric: false}
Letters [-]:
{containsNumber: false, containsAlphabet: true, alphaNumeric: true, onlyNumbers: false, onlyLetters: false, mixOfAlphaNumeric: false}
Only Special symbols :
{containsNumber: false, containsAlphabet: false, alphaNumeric: false, onlyNumbers: false, onlyLetters: false, mixOfAlphaNumeric: false}
java正则表达式模式匹配。
要测试任何字符是否为数字,无需过度修饰❓,可根据需要进行调整。
const s = "EMA618" 函数hasInt(我){ 设I = 1,a = me.split(""),b = "",c = ""; a.forEach(函数(e) { 如果(! isNaN (e)) { console.log(' contains NUMBER«${e}»AT POSITION ${a.indexOf(e)} => TOTAL COUNT ${i} ') C += e 我+ + } else {b += e} }) console.log('字符串是«${b}»,数字是«${c}»') If (i === 0){ 返回假 //返回b }其他{ 还真 //返回+c } } hasInt (s)
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