检查字符串是否在数组中以startwith开头

Question

String[] directions = {"UP","DOWN","RIGHT","LEFT"};
String input = "DOWN 123 test";

有没有办法检查输入字符串 startwith 方向中的一个值而不使用拆分输入值？

Answer 1

当然 - 只是遍历所有方向：

private static final String[] DIRECTIONS = {"UP","DOWN","RIGHT","LEFT"};

public static String getDirectionPrefix(String input) {
    for (String direction : DIRECTIONS) {
        if (input.startsWith(direction)) {
            return direction;
        }
    }
    return null;
}

或使用Java 8的流：

private static final List<String> DIRECTIONS = Arrays.asList("UP","DOWN","RIGHT","LEFT");

public static Optional<String> getDirectionPrefix(String input) {
    return DIRECTIONS.stream().filter(d -> input.startsWith(d)).findFirst();
}

Answer 2

遍历String数组并使用 <xsl:for-each select="//complextype[@name='submission']"> <td width="40%"><u>From date:</u><br/><xsl:value-of select="submission-period-from-date"/><br/></td> <td width="40%"><u>To date:</u><br/><xsl:value-of select="submission-period-to-date"/><br/></td> </xsl:for-each> 函数。

String startsWith

<强>输出

public static void main(String[] args) {
        String[] directions = { "UP", "DOWN", "RIGHT", "LEFT" };
        String input = "DOWN 123 test";

        for (String s : directions) {
            if (input.startsWith(s)) {
                System.out.println("Yes - "+s);
                break;
            } else {
                System.out.println("no - "+s);
            }
        }
    }

Answer 3

在您的情况下，您必须遍历数组并使用String.startsWith()方法。

for(String direction : directions) {
   if(input.startsWith(direction) {
      // Do something
   }
}

Answer 4

请检查以下代码。

        String[] directions = {"UP","DOWN","RIGHT","LEFT"};
String input = "DOWN 123 test";

for(String dir:directions){
    if(input.startsWith(dir)){
        System.out.println("input string starts with:"+dir);
    }
}