Java Integer Create toIntValue(final char ch)

Description

Converts the character to the Integer it represents, throwing an exception if the character is not numeric.

This method converts the char '1' to the int 1 and so on.

 CharUtils.toIntValue('3')  = 3 CharUtils.toIntValue('A')  throws IllegalArgumentException

License

Apache License

Parameter

Parameter	Description
ch	the character to convert

Exception

Parameter	Description
IllegalArgumentException	if the character is not ASCII numeric

Return

the int value of the character

Declaration

public static int toIntValue(final char ch)

Method Source Code

//package com.java2s;
/*//  www. j a  va2s  .  c  o  m
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

public class Main {
    /**
     * <p>Converts the character to the Integer it represents, throwing an
     * exception if the character is not numeric.</p>
     *
     * <p>This method converts the char '1' to the int 1 and so on.</p>
     *
     * <pre>
     *   CharUtils.toIntValue('3')  = 3
     *   CharUtils.toIntValue('A')  throws IllegalArgumentException
     * </pre>
     *
     * @param ch  the character to convert
     * @return the int value of the character
     * @throws IllegalArgumentException if the character is not ASCII numeric
     */
    public static int toIntValue(final char ch) {
        if (!isAsciiNumeric(ch)) {
            throw new IllegalArgumentException("The character " + ch + " is not in the range '0' - '9'");
        }
        return ch - 48;
    }

    /**
     * <p>Converts the character to the Integer it represents, throwing an
     * exception if the character is not numeric.</p>
     *
     * <p>This method converts the char '1' to the int 1 and so on.</p>
     *
     * <pre>
     *   CharUtils.toIntValue('3', -1)  = 3
     *   CharUtils.toIntValue('A', -1)  = -1
     * </pre>
     *
     * @param ch  the character to convert
     * @param defaultValue  the default value to use if the character is not numeric
     * @return the int value of the character
     */
    public static int toIntValue(final char ch, final int defaultValue) {
        if (!isAsciiNumeric(ch)) {
            return defaultValue;
        }
        return ch - 48;
    }

    /**
     * <p>Converts the character to the Integer it represents, throwing an
     * exception if the character is not numeric.</p>
     *
     * <p>This method converts the char '1' to the int 1 and so on.</p>
     *
     * <pre>
     *   CharUtils.toIntValue(null, -1) = -1
     *   CharUtils.toIntValue('3', -1)  = 3
     *   CharUtils.toIntValue('A', -1)  = -1
     * </pre>
     *
     * @param ch  the character to convert
     * @param defaultValue  the default value to use if the character is not numeric
     * @return the int value of the character
     */
    public static int toIntValue(final Character ch, final int defaultValue) {
        if (ch == null) {
            return defaultValue;
        }
        return toIntValue(ch.charValue(), defaultValue);
    }

    /**
     * <p>Checks whether the character is ASCII 7 bit numeric.</p>
     *
     * <pre>
     *   CharUtils.isAsciiNumeric('a')  = false
     *   CharUtils.isAsciiNumeric('A')  = false
     *   CharUtils.isAsciiNumeric('3')  = true
     *   CharUtils.isAsciiNumeric('-')  = false
     *   CharUtils.isAsciiNumeric('\n') = false
     *   CharUtils.isAsciiNumeric('&copy;') = false
     * </pre>
     *
     * @param ch  the character to check
     * @return true if between 48 and 57 inclusive
     */
    public static boolean isAsciiNumeric(final char ch) {
        return ch >= '0' && ch <= '9';
    }
}