我认为这个问题是因为条件不正确
我建议使用以下代码

Scanner scanner = new Scanner(System.in);
    String [] bands = {"guantanamo baywatch", "levitation room",
                       "allah las", "los pesos", "tijuana panthers"};

    System.out.println("give me a band name.");
    String bandInput = scanner.nextLine();

    for(String userInput : bands){
        if(bandInput.equals(userInput)){
           System.out.print("The input was found: "+userInput);
        }
    }

解决方案

因为在这里使用数组，所以包含将不起作用。必须遍历数组并检查每个项是否等于用户输入的字符串。
为了进行比较，你应该使用 .equal() 字符串方法

package hall;

import java.text.DecimalFormat;
import java.util.Arrays;

import java.util.Scanner;
public class H {
    public static void main(String[] args){
        H.THELASTQ();
    }
    @SuppressWarnings("unlikely-arg-type")
    public static void THELASTQ() {
        Scanner scanner = new Scanner(System.in);
        String[] bands = {"guantanamo baywatch", "levitation room", "allah las", "los pesos", "tijuana panthers"};

        System.out.println("give me a band name.");
        String bandInput = scanner.nextLine();

        for(int i = 0; i < bands.length; i++) {
            if(bands[i].equals(bandInput))
            {
                System.out.print("whats their best song?");
                String bestSong = scanner.nextLine();
                System.out.println("I love " + bestSong);
            }
        }

    }
}

问题是您用来比较用户输入的方法。您可以将条件更改为“if（arrays.aslist（bands.contains（bandinput））”。
例子

import java.util.Arrays;

public class Main {

    public static void main(String[] args) {
        String [] bands = {"guantanamo baywatch", "levitation room", "allah las", "los pesos", "tijuana panthers"};

        System.out.println(Arrays.asList(bands).contains("allah las"));
    }

}

输出

true