如何在不考虑空格和Java字符串大小写的情况下比较两个字符串？

Question

I have this code:

public class TestString {

    public static void main(String[] args) {
        String a = "Vijay Kakade";
        String b = "vij";

        if (a.contains(b)) {
            System.out.println("11");
        } else {
            System.out.println("22");
        }
    }
}

This example should return 11 but it returns 22.

Answer 1

You can replace spaces and use equalsIgnoreCase :

if (a.replace(" ", "").equalsIgnoreCase(b.replace(" ", ""))) {

If you want to also disregard other whitespace characters you can use replaceAll :

if (a.replaceAll("\\s", "").equalsIgnoreCase(b.replaceAll("\\s", ""))) {

---

If you want instead to check for containment , use contains and toLowerCase :

if (a.replace(" ", "").toLowerCase().contains(b.replace(" ", "").toLowerCase())) {

Again, if you want to disregard other whitespace character use replaceAll("\\\\s", "") as shown above.

Answer 2

Use replace() to remove spaces, and use toLowerCase() to bring both strings to the same case, then use contains() :

if (a.replace(" ", "").toLowerCase().contains(b.replace(" ", "").toLowerCase()))

---

To make this null safe (defining null as not equal to anything, not even another null):

if (a != null && b != null && a.replace(" ", "").toLowerCase().contains(b.replace(" ", "").toLowerCase()))

Or, if null is considered "equal" to another null:

if (!((a == null) ^ (b == null)) || a != null && a.replace(" ", "").toLowerCase().contains(b.replace(" ", "").toLowerCase()))

Answer 3

Try this

     String a = "V    i     jay Kakade";
        String b = "vI  j";
        if (a.toLowerCase().replaceAll("\\s", "").trim().contains(b.trim().toLowerCase().replaceAll("\\s", ""))) {
            System.out.println("11");
        } else {
            System.out.println("22");
        }

Answer 4

Set both a and b to lowercase and remove spaces, then make your comparison:

    String a = " V I J a y Kakade";
    String b = " V i j ";

    a = a.toLowerCase().replaceAll("\\s","");
    b = b.toLowerCase().replaceAll("\\s","");

    if (a.contains(b)) {
        System.out.println("11");
    } else {
        System.out.println("22");
    }

Answer 5

String a = " VIJ ay Kakade"; String b = " V ij ";

a = a.toLowerCase().replaceAll("\\s","");
b = b.toLowerCase().replaceAll("\\s","");

if (a.contains(b)) {
    System.out.println("11");
} else {
    System.out.println("22");
}