View Category
Strings
Printing

Output a string to the console

Write the string "Hello World!" to STDOUT
perl
print "Hello World!\n"
java
System.out.println("Hello World!");
System.out.printf("Hello World!\n");
groovy
println "Hello World!"

Retrieve a string containing ampersands from the variables in a url

My PHP script first does a query to obtain customer info for a form. The form has first name and last name fields among others. The customer has put entries such as "Ron & Jean" in the first name field in the database. Then the edit form script is called with variables such as

"http://myserver.com/custinfo/edit.php?mode=view&fname=Ron & Jean&lname=Smith".

The script variable for first name $_REQUEST['firstname'] never gets beyond the "Ron" value because of the ampersand in the data.

I have tried various functions like urldecode but all to no avail. I even tried encoding the url before the view screen is painted so that the url looks like "http://myserver/custinfo/edit.php?mode=view&fname="Ronxxnbsp;xxamp;xxnbsp;Jean"&lname=SMITH". (sorry I had to add the xx to replace the ampersand or it didn't display meaningful url contents the browser sees.)

Of course this fails for the same reasons. What is a better approach?
perl
print "http://myserver.com/custinfo/edit.php"
."?fname=".urlenc('Ron & Jean')
."&lname=".urlenc('Smith');
sub urlenc{my($s)=@_;$s=~s/([^A-Za-z0-9])/sprintf("%%%02X",ord($1))/seg;$s}
java
Map<String, String> params = new HashMap<String, String>();
params.put("mode", "view");
params.put("fname", "Ron & Jean");
params.put("lname", "Smith");

StringBuilder buffer = new StringBuilder();
for (Map.Entry<String, String> entry : params.entrySet()) {
buffer.append(URLEncoder.encode(entry.getKey(), "UTF-8"))
.append("=")
.append(URLEncoder.encode(entry.getValue(), "UTF-8"));
}
System.out.println(buffer.toString());
groovy
// Given the nature of the question text, I am assuming the question
// is how to produce a application/x-www-form-urlencoded compliant string

def basename = 'http://somedomain.com/somebase/'
def parameter = 'Bart & Lisa'
// equivalent to php
println basename + URLEncoder.encode(parameter)
// recommended approach is to specify encoding
println basename + URLEncoder.encode(parameter, "UTF-8")

string-wrap

Wrap the string "The quick brown fox jumps over the lazy dog. " repeated ten times to a max width of 78 chars, starting each line with "> "

Expected output:
> The quick brown fox jumps over the lazy dog. The quick brown fox jumps over t
> he lazy dog. The quick brown fox jumps over the lazy dog. The quick brown fox
> jumps over the lazy dog. The quick brown fox jumps over the lazy dog. The qui
> ck brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy
> dog. The quick brown fox jumps over the lazy dog. The quick brown fox jumps o
> ver the lazy dog. The quick brown fox jumps over the lazy dog.
java
public class SolutionXX {
public static void main(String[] args) {
StringBuilder builder = new StringBuilder();
String words = "The quick brown fox jumps over the lazy dog. ";

for (int i = 0; i < 10; i++)
{
builder.append(words);
}

String toWrap = builder.toString();
int width = 76;
while (toWrap!=null && toWrap.length()>0)
{
String first = toWrap.length() > width ? toWrap.substring(0, width+1) : toWrap;
toWrap = (!toWrap.equals(first)) ? toWrap.substring(width + 1).trim() : null;
System.out.println("> " + first);
}

}
}
groovy
'The quick brown fox jumps over the lazy dog. '.multiply(10).split('(?<=\\G.{76})').each{println '> ' + it}
st = "The quick brown fox jumps over the lazy dog. " * 10
width = 76
while(st){
(first, st) = st.length() > width? [st[0..width], st[(width+1)..-1].trim()] : [st, null]
println "> $first"
}
Declaration

Define a string containing special characters

Define the literal string "\#{'}${"}/"
perl
$special = '\#{\'}${"}/';
$special = q(\#{'}${"}/);
java
String special = "\\#{'}${\"}/";
groovy
special = "\\#{'}\${\"}/"
special = '\\#{\'}${"}/'
special = /\#{'}${'$'}{"}\//

Define a multiline string

Define the string:
"This
Is
A
Multiline
String"
perl
$text = 'This
Is
A
Multiline
String';
$text = <<EOF;
This
Is
A
Multiline
String
EOF
java
String text = "This\nIs\nA\nMultiline\nString";
String text =
"This\n" +
"Is\n" +
"A\n" +
"Multiline\n" +
"String"
groovy
def text =
"""This
Is
A
Multiline
String"""
def text = "This\nIs\nA\nMultiline\nString"

Define a string containing variables and expressions

Given variables a=3 and b=4 output "3+4=7"
perl
print "$a+$b=${\($a+$b)}\n";
sprintf("%d+%d=%d", $a, $b, $a + $b);
print $a, '+', $b, '=', $a + $b;
java
System.out.println(a + "+" + b + "=" + (a+b));
System.out.printf("%d+%d=%d\n", a, b, a + b);
groovy
println "$a+$b=${a+b}"
printf "%d+%d=%d\n", a, b, a + b
Manipulation

Reverse the characters in a string

Given the string "reverse me", produce the string "em esrever"
perl
$_ = reverse "reverse me"; print
java
String reverse = new StringBuffer("reverse me").reverse().toString();
String reverse = new StringBuilder("reverse me").reverse().toString();
String reverse = StringUtils.reverse("reverse me");
groovy
reversed = "reverse me".reverse()

Reverse the words in a string

Given the string "This is a end, my only friend!", produce the string "friend! only my end, the is This"
perl
$reversed = join ' ', reverse split / /, $text;
java
List list = new ArrayList();
StringTokenizer st = new StringTokenizer(text, " ");
while(st.hasMoreTokens()) {
list.add(0, st.nextToken());
}
StringBuffer sb = new StringBuffer();
for (Iterator iterator = list.iterator(); iterator.hasNext();) {
String word = (String) iterator.next();
sb.append(word);
if (iterator.hasNext()) {
sb.append(" ");
}
}
String reversed = sb.toString();
List<String> ls = Arrays.asList("This is the end, my only friend!".split("\\s"));
Collections.reverse(ls);
StringBuilder sb = new StringBuilder(32); for (String s : ls) sb.append(" ").append(s);
String reversed = sb.toString().trim();
String reversed = StringUtils.reverseDelimited("This is the end, my only friend!", ' ');
groovy
reversed = "This is the end, my only friend!".split().reverse().join(' ')
reversed = "This is the end, my only friend!".tokenize(' ').reverse().join(' ')
def revdelim(c, s) { StringUtils.reverseDelimited(s, c) }
revwords = this.&revdelim.curry(" " as char)
reversed = revwords("This is the end, my only friend!")
reversed = StringUtils.reverseDelimited("This is the end, my only friend!", " " as char)

Text wrapping

Wrap the string "The quick brown fox jumps over the lazy dog. " repeated ten times to a max width of 78 chars, starting each line with "> ", yielding this result:

> The quick brown fox jumps over the lazy dog. The quick brown fox jumps
> over the lazy dog. The quick brown fox jumps over the lazy dog. The
> quick brown fox jumps over the lazy dog. The quick brown fox jumps
> over the lazy dog. The quick brown fox jumps over the lazy dog. The
> quick brown fox jumps over the lazy dog. The quick brown fox jumps
> over the lazy dog. The quick brown fox jumps over the lazy dog. The
> quick brown fox jumps over the lazy dog.
perl
use Text::Wrap;
$text = "The quick brown fox jumps over the lazy dog. ";
$Text::Wrap::columns = 73;
print wrap('> ', '> ', $text x 10);
$_ = "The quick brown fox jumps over the lazy dog. " x 10;
s/(.{0,70}) /> $1\n/g;
print;
java
String prefix = "> "; String input = "The quick brown fox jumps over the lazy dog.";

String[] lines = WordUtils.wrap(StringUtils.repeat(input, 10), 72 - prefix.length()).split("\n");

for (String line : lines) System.out.printf("%s%s\n", prefix, line);
groovy
// no built-in fill, define one using brute force approach
def fill(text, width=80, prefix='') {
width = width - prefix.size()
def out = []
List words = text.replaceAll("\n", " ").split(" ")
while (words) {
def line = ''
while (words) {
if (line.size() + words[0].size() + 1 > width) break
if (line) line += ' '
line += words[0]
words = words.tail()
}
out += prefix + line
}
out.join("\n")
}
println fill('The quick brown fox jumps over the lazy dog. ' * 10, 72, '> ')
// no built-in fill, define one using lastIndexOf
def fill(text, width=80, prefix='') {
def out = ''
def remaining = text.replaceAll("\n", " ")
while (remaining) {
def next = prefix + remaining
def found = next.lastIndexOf(' ', width)
if (found == -1) remaining = ''
else {
remaining = next.substring(found + 1)
next = next[0..found]
}
out += next + '\n'
}
out
}
println fill('The quick brown fox jumps over the lazy dog. ' * 10, 72, '> ')
prefix = '> '
input = 'The quick brown fox jumps over the lazy dog. '
wrap(input * 10, 72 - prefix.size()).eachLine{ println prefix + it }

Remove leading and trailing whitespace from a string

Given the string "  hello    " return the string "hello".
perl
my $string = " hello ";
$string =~ s{
\A\s* # Any number of spaces at the start of the string
(.+?) # Remember any number of characters until we reach
\s*\z # any number of spaces at the end of the string
}{
$1 # Leave the characters we remembered
}x;
my $string = " hello ";
$string =~ s{\A\s*}{};
$string =~ s{\s*\z}{};

#Modification History:
# 2009-MAR-17: GGARIEPY: [creation] (geoff.gariepy@gmail.com)

$string = " hello ";
$string =~ s/^\s+|\s+$//g; # All the action happens in one regex!

# Regex Notes:
# ^ - anchors to the beginning of the string
# $ - anchors to the end of the string
# g - causes regex to match as many times as possible
# | - logical OR
java
String s = " hello "; String trimmed = s.trim();
groovy
assert "hello" == " hello ".trim()

Simple substitution cipher

Take a string and return the ROT13 and ROT47 (Check Wikipedia) version of the string.
For example:
String is: Hello World #123
ROT13 returns: Uryyb Jbeyq #123
ROT47 returns: w6==@ (@C=5 R`ab
perl
sub rot13 {
my $str = shift;
$str =~ tr/A-Za-z/N-ZA-Mn-za-m/;
return $str;
}

sub rot47 {
my $str = shift;
$str =~ tr/!-~/P-~!-O/;
return $str;
}

my $string = 'Hello World #123';

print "$string\n";
print rot13($string)."\n";
print rot47($string)."\n";
java
CharArrayWriter rot13 = new CharArrayWriter() ;
for (char c : i ) {
char lc = Character.toLowerCase(c) ;
rot13.append( c += ( (lc >= 'a' && lc <= 'm') ? 13 : ( (lc >= 'n' && lc <= 'z') ? -13 : 0 ) )) ;
}

CharArrayWriter rot47 = new CharArrayWriter() ;
for (char c : i )
rot47.append( c += ( (c >= '!' && c <= 'O') ? 47 : ( (c >= 'P' && c <= '~') ? -47 : 0 ) )) ;
groovy
char rot13(s) {
char c = s
switch(c) {
case 'A'..'M': case 'a'..'m': return c+13
case 'N'..'Z': case 'n'..'z': return c-13
default : return c
}
}
String.metaClass.rot13 = {
delegate.collect(this.&rot13).join()
}

from = '!"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~'
to = 'PQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~!"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNO'
String.metaClass.rot47 = {
delegate.collect{ int found = from.indexOf(it); found < 0 ? it : to[found] }.join()
}

assert 'Hello World #123'.rot13() == 'Uryyb Jbeyq #123'
assert 'Hello World #123'.rot47() == 'w6==@ (@C=5 R`ab'
Case

Make a string uppercase

Transform "Space Monkey" into "SPACE MONKEY"
perl
print uc "Space Monkey"
java
String upper = text.toUpperCase();
groovy
println "Space Monkey".toUpperCase()

Make a string lowercase

Transform "Caps ARE overRated" into "caps are overrated"
perl
print lc "Caps ARE overRated"
java
"Caps ARE overRated".toLowerCase();
groovy
println "Caps ARE overRated".toLowerCase()

Capitalise the first letter of each word

Transform "man OF stEEL" into "Man Of Steel"
perl
$text =~ s/(\w+)/\u\L$1/g;
java
String input = "man OF stEEL";
StringTokenizer tokenizer = new StringTokenizer(input);
StringBuffer sb = new StringBuffer();
while (tokenizer.hasMoreTokens()) {
String word = tokenizer.nextToken();
sb.append(word.substring(0, 1).toUpperCase());
sb.append(word.substring(1).toLowerCase());
sb.append(' ');
}
String text = sb.toString();
StringBuilder sb = new StringBuilder("man OF stEEL"); String s = sb.toString();
int last = s.length() - 1;

for (int i = 0; i <= last; ++i)
if (Character.isSpaceChar(s.charAt(i)) && i < last) { ++i; sb.setCharAt(i, Character.toUpperCase(s.charAt(i))); }
else if (i == 0) sb.setCharAt(i, Character.toUpperCase(s.charAt(i)));
else sb.setCharAt(i, Character.toLowerCase(s.charAt(i)));
Matcher m = Pattern.compile("(\\w+)").matcher("man OF stEEL"); StringBuffer sb = new StringBuffer(32), rsb = new StringBuffer(8);

while (m.find())
{
rsb.replace(0, rsb.length(), m.group().toLowerCase()); rsb.setCharAt(0, Character.toUpperCase(rsb.charAt(0)));
m.appendReplacement(sb, rsb.toString());
}
m.appendTail(sb);
String text = WordUtils.capitalizeFully("man OF stEEL");
groovy
def capitalize(s) { s[0].toUpperCase() + s[1..-1].toLowerCase() }
caps = "man OF stEEL".replaceAll(/\w+/) { w -> capitalize(w) }
caps = "man OF stEEL".replaceAll(/\w+/) { w -> StringUtils.capitalize(w.toLowerCase()) }
caps = WordUtils.capitalizeFully("man OF stEEL")