Java determines whether a string contains numbers

In java, you can use the java.lang.character.isDigit(); method to determine whether a character is a number. In java, you can traverse a string and use java.lang.character. isDigit(); method determines whether there are numbers in it.

Declaration of java.lang.Character.isDigit() method

public static boolean isDigit(char ch)

Parameters: ch - the character to be tested

Return value: If the character is a number, this method returns true, otherwise false is returned.

Example:

public static void main(String[] args){
boolean isDigit = false;//定义一个boolean值，用来表示是否包含数字
boolean isLetter = false;//定义一个boolean值，用来表示是否包含字母
String str = "aaasss8fff"; //假设有一个字符串
for(int i=0 ; i<str.length() p="" 循环遍历字符串
if(Character.isDigit(str.charAt(i))){ //用char包装类中的判断数字的方法判断每一个字符
isDigit = true;
}
if(Character.isLetter(str.charAt(i))){ //用char包装类中的判断字母的方法判断每一个字符
isLetter = true;
}
}

For more java knowledge, please pay attention to java basic tutorial.

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