Java charAt().equals() 导致“char 不能被取消引用”
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charAt().equals() causes "char cannot be dereferenced"
提问by Ds.109
I am trying to check a string for hyphens at different positions (for a phone number because the input varies), but I keep getting the error
我正在尝试检查不同位置的连字符字符串（对于电话号码，因为输入不同），但我不断收到错误
char cannot be dereferenced
char 不能取消引用
Code:
代码：
do {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.print("Enter String");
String raw = br.readLine();
if (raw.length() < 10) {
System.out.println("");
System.out.println("Please input a valid phone number of at least 10 digits/letters");
System.out.println("");
} else {
if (raw.charAt(3).equals('-') && raw.charAt(7).equals('-')) {
System.out.println("2 Hyphens at 3 and 7");
} else if (raw.charAt(3).equals('-')
&& raw.charAt(8).equals('-')) {
System.out.println("2 Hyphens at 3 and 8");
} else if (raw.charAt(3).equals('-')
&& raw.charAt(9).equals('-')) {
System.out.println("2 Hyphens at 3 and 9");
}
}
} while (1 < 2);
采纳答案by N Alex
If you use something like this, it will work:
如果你使用这样的东西，它会起作用：
if (raw.charAt(3) == '-' && raw.charAt(7) == '-') {
System.out.println("2 Hyphens at 3 and 7");
} else if (raw.charAt(3) == '-' && raw.charAt(8) == '-') {
System.out.println("2 Hyphens at 3 and 8");
} else if (raw.charAt(3) == '-' && raw.charAt(9) == '-') {
System.out.println("2 Hyphens at 3 and 9");
}
The problem is that raw.charAt(n)returns a charand not a String. The equals()method can be used only on objects. Char is a primitive data typewhich has no methods. On chars you should use operators like ==or !=.
问题是raw.charAt(n)返回 achar而不是 a String。该equals()方法只能用于对象。Char 是一种没有方法的原始数据类型。在字符上，您应该使用像==或这样的运算符!=。
