如何在Java字符串数组中查找特定字符的整数值？

Question

I am using the following code to take a string value like 9s or 4c that is located within a string array and find just the integer value of the first character. I would also like to be able to use this for string values with multiple numbers like 10s or 13c.

total = total + Integer.parseInt(a[i].substring(0)) + 1;

This gives me a number format exception. Any ideas what I might be doing wrong?

Answer 1

This will work

public static void getIntVal()  {
    String text = "123cc";
    String numOnly = text.replaceAll("\\D+", "");
    int numVal = Integer.valueOf(numOnly);
    System.out.println(numVal);
}

IF some one want to use as double, you can do it as follows

    String text = "123.0114cc";
    String numOnly = text.replaceAll("\\p{Alpha}","");
    double numVal = Double.valueOf(numOnly);
    System.out.println(numVal);

Answer 2

str.substring(0) is just str again (read the docs ). You are probably looking for

a[i].substring(0, a[i].length() - 1)  // cuts off last character

Answer 3

Ruchira's solution prescribes removal of non digit characters; which in your setup seems right. However, her solution is invalid if the numbers are floats or doubles as shreyansh jogi questions.

Implementing Ruchira's thought solution properly, this would solve your problem...

String text = "123.0121cc";
String numOnly = text.replaceAll("\\p{Alpha}", "");

If you know what to expect, say double : double numVal = Double.valueOf(numOnly); System.out.println(numVal);

Otherwise.. if you don't know whether the rest of the text is integer or double , this would help you:

if(numOnly.contains(".")) {
    double numVal = Double.valueOf(numOnly);
    System.out.println(numVal);
} else {
    int numVal = Integer.valueOf(numOnly);
    System.out.println(numVal);
}

Answer 4

total = total + Integer.parseInt(a[i].substring(0,a[i].length()-1));