JAVA

how to instantiate hashmap in java

Map<String, String> doubleBraceMap  = new HashMap<String, String>() {{
    put("key1", "value1");
    put("key2", "value2");
}};

public static Map<String, String> articleMapOne;
static {
    articleMapOne = new HashMap<>();
    articleMapOne.put("ar01", "Intro to Map");
    articleMapOne.put("ar02", "Some article");
}

Initialize HashMap Java

public static Map<String, Object> map(Object... keyValues) {
    Map<String, Object> map = new HashMap<>();
    for (int i = 0; i < keyValues.length; i = i + 2) {
        map.put((String) keyValues[i], keyValues[i + 1]);
    }
    return map;
}

// usage
Map<String, String> student = MapUtils.map("firstname", "Jack", "age", "18");