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javastringint

Java convert string to int

I have a string. I split and store it as a char array . I am trying to convert it using Integer.parseInt and I get an error. How do I convert String to int?

Here's my code:

String tab[]= null;
tab=pesel.split("");
int temp=0;
for(String tab1 : tab)
{
    temp=temp+3*Integer.parseInt(tab1); //error
}
Solution

  • Assuming you have a string of digits (e.g. "123"), you can use toCharArray() instead:

    for (char c : pesel.toCharArray()) {
    temp += 3 * (c - '0');
}

    This avoids Integer.parseInt() altogether. If you want to ensure that each character is a digit, you can use Character.isDigit().

    Your error is because str.split("") contains a leading empty string in the array:

    System.out.println(Arrays.toString("123".split("")));

    [, 1, 2, 3]

    Now, there is a trick using negative lookaheads to avoid that:

    System.out.println(Arrays.toString("123".split("(?!^)")));

    [1, 2, 3]

    Although, in any case, I would prefer the approach shown above.