how to check is a string is a number code example

Example 1: java check if string is number

try {
    int n = Integer.parseInt(str);
} catch (NumberFormatException e) {
    // str is not a number
}

Example 2: how to check a number in string

To find whether a given string contains a number,
convert it to a character array and find whether 
each character in the array is a digit using the isDigit() 
method of the Character class