Summary of Java methods for determining whether a string is a number
- 2020-04-01 04:20:56
- OfStack
This example summarizes the Java method for determining whether a string is a number. Share with you for your reference, as follows:
Method 1: use the functions that come with JAVA
public static boolean isNumeric(String str){
for (int i = str.length();--i>=0;){
if (!Character.isDigit(str.charAt(i))){
return false;
}
}
return true;
}
Method 2: use regular expressions
public static boolean isNumeric(String str){
Pattern pattern = Pattern.compile("[0-9]*");
return pattern.matcher(str).matches();
}
Method 3: use ASCII code
public static boolean isNumeric(String str){
for(int i=str.length();--i>=0;){
int chr=str.charAt(i);
if(chr<48 || chr>57)
return false;
}
return true;
}
I hope this article has been helpful to you in Java programming.