用java语言判断String字符串是否是回文（忽略大小写和分隔符）_JAVA_编程开发_程序员俱乐部

判断String字符串是否是回文

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用到的方法

String.charAt(int i);// 返回指定索引处的 char 值

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Character.isLetter(int codePoint);// 确定指定字符（Unicode 代码点）是否为字母

Character.isLetter(char c);// 确定指定字符是否为字母

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Character.isDigit(int codePoint);// 确定指定字符（Unicode 代码点）是否为数字

Character.isDigit(char c);// 确定指定字符是否为数字

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Character.toLowerCase(int codePoint);//将字符（Unicode 代码点）参数转换为小写

Character.toLowerCase(char c);// 将字符参数转换为小写

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Character.toUpperCase(int codepoint);Character.toUpperCase(char c);//参见toLowerCase

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判断回文（忽略大小写，分隔符）?

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//A.java

public?class?A?{

????public?static?void?main(String[]?args)?{
????????String?str?=?"Madam,?I'm?Adam";
????????if?(exec(str))?{
????????????System.out.println("is?palindrome");
????????}?else?{
????????????System.out.println("not");
????????}
????}

????public?static?boolean?exec(String?str)?{
????????for?(int?i?=?0,?j?=?str.length()?-?1;?i?<?j;?i++,?j--)?{
????????????while?(!Character.isLetter(str.charAt(i)))?{
????????????????i++;
????????????}
????????????while?(!Character.isLetter(str.charAt(j)))?{
????????????????j--;
????????????}
????????????if?(Character.toLowerCase(str.charAt(i))?!=?Character.toLowerCase(str.charAt(j)))?{
????????????????return?false;
????????????}
????????}
????????return?true;
????}
}

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