Is there any single line of code that can be used to calculate the number of digits in a program? I mean to say, can be there a reference to a class (such as String.length for a String) which can be used to calculate the number of digits in a number?
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cast int to string and use this methog – Kick Mar 03 '14 at 17:10
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Do you have the value as a number (int, long, double, char) or as a String? – Sotirios Delimanolis Mar 03 '14 at 17:10
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http://stackoverflow.com/questions/1306727/way-to-get-number-of-digits-in-an-int – assylias Mar 03 '14 at 17:11
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4Which type of number - there any many: integer, float, short, double, decimal... – Rich O'Kelly Mar 03 '14 at 17:11
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no need for valueOf() despite most of the answers, ("" + number) is a string. – La-comadreja Mar 03 '14 at 17:13
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I need to calculate the length of an Integer Number. – Niluu Mar 03 '14 at 17:13
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Or is there any line of code to parse an Integer into a String? – Niluu Mar 03 '14 at 17:14
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concatenate the integer to the end of an empty string: ("" + number) – La-comadreja Mar 03 '14 at 17:15
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Just one last Question, is there a Syntax like (Integer. ...) – Niluu Mar 03 '14 at 17:17
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This question was closed for the wrong reason: it's clear what this question is asking, and it's actually a duplicate of http://stackoverflow.com/questions/1306727/way-to-get-number-of-digits-in-an-int. – Anderson Green Mar 03 '14 at 17:26
7 Answers
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If you want to avoid converting to a String (and convert to a double and back to an int instead):
digits = int(Math.log10(a)) + 1;
If you also need to handle negative numbers:
digits = int(Math.log10(Math.abs(a))) + 1;
// uncomment the following line to count the negative sign as a digit
// if (a < 0) { digits += 1; }
Brigham
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+1, as the log approach is about 20 times faster than the string conversion one. – Danstahr Mar 03 '14 at 17:19
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Use
Math.floor(Math.log10(num)) + 1
for integers. Use
String.valueOf(num).length()
for anything else
PlasmaPower
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int a = 125846;
System.out.println("Length is "+String.valueOf(a).length());
Output:
Length is 6
Uyghur Lives Matter
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Kick
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int bubba = 56733;
System.out.println(String.valueOf(bubba).length());
Output: 5
Solace
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Integer.toString(19991).length();
Graham Griffiths
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The method is called `toString()`. Remember that Java convention is that method starts with lowercase, classes with uppercase. – Christian Tapia Mar 03 '14 at 17:23
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