检查用户输入的字符串是否只包含大写 and/or 小写字母

Question

我正在创建一个 Chrome 扩展程序，将核苷酸序列转换成相应的氨基酸，我运行在验证用户输入方面遇到了一些问题。

我最终想检查以确保用户只输入了大写或小写字符（没有数字、特殊字符、空格等）。如果发现任何不可接受的字符，它会警告用户输入无效。否则，程序将照常进行，不会抛出 error/alert。

下面是我目前拥有的 JavaScript 代码。我已经尝试了一些基于 this post but I can't seem to get anything to work for me. With the code I have right now, when I try to submit valid input ("ATG" for example), the alert pops up instead of the program proceeding as normal and correctly outputting "M" (see this link 的变体以供参考。

document.getElementById('button').onclick = function () {

    console.log(document.querySelectorAll("textarea"))
    var n_seq = document.querySelectorAll("textarea")[0].value.toUpperCase();


    // validate user input below
    if (!/^[a-zA-Z]+$/i.test(n_seq)); {
        alert("invald input");
        return;
    }


document.getElementById("amino_acid_seq").value = translateInput(codonDict, n_seq);

}

Answer 1

我相信这会有所帮助。

//this will make the entire string uppercase
// that way you do not need to tell user to make sure its upper case
var input = document.querySelectorAll("textarea").toUpperCase();
//this is regex that will tell if its all letters. the i makes it case insesitve 
var reg = /^[a-z]+$/i;
//this should output true or false
console.log( reg.test(input) );

Answer 2

使用此模式检查：/^[a-zA-Z]+$/i.test(yourStr);

Answer 3

这最终对我有用：

// only letters are acceptable characters, spaces, special characters, and 
// numbers will throw an error
if (!/^[A-Z]+$/i.test(n_seq)) {
    alert("Invalid input!");
    return;
}

检查用户输入的字符串是否只包含大写 and/or 小写字母

Check if user input string contains only uppercase and/or lowercase letters

javascript

google-chrome

dna-sequence

google-chrome-extension