Test to see if this string contains only US-ASCII (i.e., 7-bit ASCII) Characters. - Java java.lang

Java examples for java.lang:Assert

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Description

Test to see if this string contains only US-ASCII (i.e., 7-bit ASCII) Characters.

Demo Code

/*//from w  w w . j a  v a2s  . c  om
 * 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.
 */
//package com.java2s;

public class Main {
    public static void main(String[] argv) throws Exception {
        String s = "java2s.com";
        System.out.println(isAscii(s));
    }

    /**
     * Test to see if this string contains only US-ASCII (i.e., 7-bit
     * ASCII) Characters.
     *
     * @param s      The test string.
     *
     * @return true if this is a valid 7-bit ASCII encoding, false if it
     *         contains any non-US ASCII characters.
     */
    static public boolean isAscii(String s) {
        for (int i = 0; i < s.length(); i++) {
            if (!isAscii(s.charAt(i))) {
                return false;
            }
        }
        return true;
    }

    /**
     * Test to see if a given character can be considered "valid" ASCII.
     * The excluded characters are the control characters less than
     * 32, 8-bit characters greater than 127, EXCEPT the CR, LF and
     * tab characters ARE considered value (all less than 32).
     *
     * @param ch     The test character.
     *
     * @return true if this character meets the "ascii-ness" criteria, false
     *         otherwise.
     */
    static public boolean isAscii(int ch) {
        // these are explicitly considered valid.
        if (ch == '\r' || ch == '\n' || ch == '\t') {
            return true;
        }

        // anything else outside the range is just plain wrong.
        if (ch >= 127 || ch < 32) {
            return false;
        }
        return true;
    }
}

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