Question

可能重复：
How do I compare strings in Java?

我有以下代码但由于某种原因它不会更改字符串

accountClass返回字符串“L”

String accountClass = accClass.substring(4, 5);
        if (accountClass == "A") {
            accountClass = "Staff - A";
        } else if (accountClass == "B") {
            accountClass = "Student - B";
        } else if (accountClass == "H") {
            accountClass = "Personal - H";
        } else if (accountClass == "K") {
            accountClass = "60 Plus - K";
        } else if (accountClass == "L") {
            accountClass = "Business - L";
        } else if (accountClass == "P") {
            accountClass = "Charity - P";
        } else if (accountClass == "Q") {
            accountClass = "AIB Subsidiary - Q";
        } else if (accountClass == "X") {
            accountClass = "Irish State Spons & Sub's - X";
        } else if (accountClass == "Y") {
            accountClass = "Other Companies & Orgs - Y";
        } else if (accountClass == "Z") {
            accountClass = "Impersonal & Gen. Ledger - Z";
        }

我只是想知道它是= =导致问题还是别的什么？

Answer 1

始终使用equals（）方法检查字符串相等性。如果对象==检查两个引用变量是否引用同一个实例。使用String.equals()方法检查两个字符串是否有意义相等。

if (accountClass == "A") {

应该是

if (accountClass.equals("A")) {

你的其他if语句也是如此。

Answer 2

刚才意识到它应该是if（accountClass.equals（“L”））

Java if else语句更改字符串

2 个答案: