Gets the Unicode code point at the given index of the string. - Java java.lang

Java examples for java.lang:String Unicode

  1. HOME
  2. Java
  3. java.lang
  4. String Unicode

Description

Gets the Unicode code point at the given index of the string.

Demo Code

/*// ww  w . j  a v  a  2 s . c o  m
 Written in 2013 by Peter O.
 Any copyright is dedicated to the Public Domain.
 http://creativecommons.org/publicdomain/zero/1.0/
 If you like this, you should donate to Peter O.
 at: http://upokecenter.dreamhosters.com/articles/donate-now-2/
 */
//package com.java2s;

public class Main {
    /**
     * Gets the Unicode code point at the given index of the string.
     * @param str A string.
     * @param index Index of the current position into the string.
     * @return The Unicode code point at the given position. Returns -1 if {@code
     * index} is less than 0, or is the string's length or greater. Returns
     * the replacement character (U + FFFD) if the current character is an
     * unpaired surrogate code point.
     * @throws NullPointerException The parameter {@code str} is null.
     */
    public static int CodePointAt(String str, int index) {
        return CodePointAt(str, index, 0);
    }

    /**
     * Gets the Unicode code point at the given index of the string.
     * @param str A string.
     * @param index Index of the current position into the string.
     * @param surrogateBehavior Specifies what kind of value to return if the
     * previous character is an unpaired surrogate code point: if 0, return
     * the replacement character (U + FFFD); if 1, return the value of the
     * surrogate code point; if neither 0 nor 1, return -1.
     * @return The Unicode code point at the current position. Returns -1 if {@code
     * index} is less than 0, or is the string's length or greater. Returns
     * a value as specified under {@code surrogateBehavior} if the previous
     * character is an unpaired surrogate code point.
     * @throws NullPointerException The parameter {@code str} is null.
     */
    public static int CodePointAt(String str, int index,
            int surrogateBehavior) {
        if (str == null) {
            throw new NullPointerException("str");
        }
        if (index >= str.length()) {
            return -1;
        }
        if (index < 0) {
            return -1;
        }
        int c = str.charAt(index);
        if ((c & 0xfc00) == 0xd800 && index + 1 < str.length()
                && str.charAt(index + 1) >= 0xdc00
                && str.charAt(index + 1) <= 0xdfff) {
            // Get the Unicode code point for the surrogate pair
            c = 0x10000 + ((c - 0xd800) << 10)
                    + (str.charAt(index + 1) - 0xdc00);
            ++index;
        } else if ((c & 0xf800) == 0xd800) {
            // unpaired surrogate
            return (surrogateBehavior == 0) ? 0xfffd
                    : ((surrogateBehavior == 1) ? c : (-1));
        }
        return c;
    }
}

Related Tutorials