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|
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Create / delete
|
Create string
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String a = "";
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a = new String("abcdef");
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abcdef
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Initialise
|
Fixed contents
|
a = "";
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a = "abcdef";
|
abcdef
|
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Repeated value 'x' x 10
|
a = "";
|
ca = new char [10]; Arrays.fill(ca,'x'); a=String.valueOf(ca);
|
xxxxxxxxxx
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Count
|
Length of string
|
a="abc";
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i=a.length();
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3
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Retrieve by index
|
Retrieve 1st char
|
a="abc";
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c=a.charAt(0);
|
a
|
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Retrieve last char
|
a="abc";
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c=a .charAt(a.length()-1);
|
c
|
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Retrieve char 'n'
|
a="abcdef";
n=2;
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c=a.charAt(n);
|
c
|
Slice
|
Slice from index 'm' to 'n' (inclusive)
|
a="abcdefghi";
m=3;
n=6;
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s=a.substring(m,n+1);
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defg
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Slice from index 'n' (inclusive)
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a="abcdefghi";
n=3;
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s=a.substring(n);
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defghi
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|
Slice up to index 'n' (inclusive)
|
a="abcdefghi";
n=3;
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s=a.substring(0,n+1);
|
abcd
|
Compare
|
Test for equality (case sensitive)
|
a="abcdef";
b="abc";
|
t=a.equals(b);
|
0
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Test for equality (case insensitive)
|
a="abcdef";
b="ABCdef";
|
t=a.equalsIgnoreCase(b);
|
1
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Test for prefix
|
a="abcdef";
b="abc";
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t=a.startsWith(b);
|
1
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Test for suffix
|
a="abcdef";
b="def";
|
t=a.endsWith(b);
|
1
|
Search
|
Test char 'is in' string
|
a="abcdefghi";
c='c';
|
t=(a.indexOf(c)!=-1);
|
1
|
|
Test substring 'is in' string
|
a="abcdefghi";
b="abc";
|
t=(a.indexOf(b)!=-1);
|
1
|
|
Find index of char (forward)
|
a="abcdefccccc";
c='c';
|
i=a.indexOf(c);
|
2
|
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Find index of char (reverse)
|
a="abcdefccccc";
c='c';
|
i=a.lastIndexOf(c);
|
10
|
|
Find index of substring (forward)
|
a="abcdefabc";
b="abc";
|
i=a.indexOf(b);
|
0
|
|
Find index of substring (reverse)
|
a="abcdefabc";
b="abc";
|
i=a.lastIndexOf(b);
|
6
|
Split
|
Split on char
|
a="one,two,three";
b=",";
|
sa=a.split(b);
|
one two three
|
|
Split on string
|
a="aa_x_bb_x_cc";
b="_x_";
|
sa=a.split(b);
|
aa bb cc
|
Iterate
|
Iterate through string
|
a="abcdef";
b="";
|
for (i=0; i<a.length(); i++)
{ b=b+a.charAt(i); b=b+","; }
|
a,b,c,d,e,f,
|
Insert
|
Prepend char
|
a="bcdef";
c='a';
|
a=c+a;
|
abcdef
|
|
Prepend char
|
a="bcdef";
|
sb = new StringBuffer(a); sb.insert(0,'a'); a=sb.toString();
|
abcdef
|
|
Append char
|
a="abc";
c='d';
|
a=a+c;
|
abcd
|
|
Append char
|
a="abc";
c='d';
|
sb=new StringBuffer(a); sb.append(c); a=sb.toString();
|
abcd
|
|
Insert char at index 'n'
|
a="abc";
n=1;
c='X';
|
a=a .substring(0 ,n)+c+a.substring(n);
|
aXbc
|
|
Insert char at index 'n'
|
a="abc";
n=1;
c='X';
|
sb=new StringBuffer(a); sb.insert(n,c); a=sb.toString();
|
aXbc
|
|
Prepend string
|
a="def";
b="abc";
|
a=b+a;
|
abcdef
|
|
Append string
|
a="abc";
b="def";
|
a+=b;
|
abcdef
|
|
Insert string at index 'n'
|
a="abcghi";
b="def";
n=3;
|
a=a.substring(0,n) + b + a.substring(n);
|
abcdefghi
|
|
Insert string at index 'n'
|
a="abcghi";
b="def";
n=3;
|
sb=new StringBuffer(a); sb.insert(n,b); a=sb.toString();
|
abcdefghi
|
|
Concatenate 'a' and 'b'
|
a="abc";
b="def";
|
s=a+b;
|
abcdef
|
Overwrite
|
Overwrite char at index 'n'
|
a="abc";
n=1;
c='B';
|
a=a .substring(0 ,n)+c+a.substring(n+1);
|
aBc
|
|
Overwrite char at index 'n'
|
a="abc";
n=1;
c='B';
|
sb=new StringBuffer(a); sb.setCharAt(n,c); a=sb.toString();
|
aBc
|
Replace
|
Replace 1st instance of char 'X' with 'Y'
|
a="XXXYYYZZZ";
|
a=a .replaceFirst("X","Y");
|
YXXYYYZZZ
|
|
Replace all instances of char 'X' with 'Y'
|
a="XXXYYYZZZ";
|
a=a.replace('X','Y');
|
YYYYYYZZZ
|
|
Replace 1st instance of substring 'abc' with 'XYZ'
|
a="abcdefabc";
|
a=a .replaceFirst("abc" ,"XYZ");
|
XYZdefabc
|
|
Replace all instances of substring 'abc' with 'XYZ'
|
a="abcdefabc";
|
a=a .replaceAll("abc" ,"XYZ");
|
XYZdefXYZ
|
|
Replace all instances of 'X','Y','Z' with 'A','B','C' respectively
|
a="XXXYYYZZZ";
|
a=a .replace('X' ,'A') .replace('Y' ,'B').replace('Z','C');
|
AAABBBCCC
|
Remove
|
Remove 1st instance of char 'X'
|
a="XXXYYYZZZ";
|
a=a .replaceFirst("X","");
|
XXYYYZZZ
|
|
Remove all instances of char 'X'
|
a="XXXYYYZZZ";
|
a=a.replaceAll("X","");
|
YYYZZZ
|
|
Remove 1st instance of substring 'abc'
|
a="abcdefabc";
|
a=a .replaceFirst("abc","");
|
defabc
|
|
Remove all instances of substring 'abc'
|
a="abcdefabc";
|
a=a .replaceAll("abc","");
|
def
|
|
Remove prefix 'abc.'
|
a="abc.abc.def";
|
a=a .replaceFirst("^abc[.]" ,"");
|
abc.def
|
|
Remove suffix '.def'
|
a="abc.def.def";
|
a=a .replaceFirst("[.]def$" ,"");
|
abc.def
|
Remove by index
|
Remove 1st char
|
a="abcdef";
|
a=a .substring(1 ,a.length());
|
bcdef
|
|
Remove last char
|
a="abcdefghi";
|
a=a .substring(0 ,a.length()-1);
|
abcdefgh
|
|
Remove char at index 'n'
|
a="abcdef";
n=3;
|
a=a .substring(0 ,n)+a.substring(n+1);
|
abcef
|
|
Remove chars in index range 'm' to 'n' (inclusive)
|
a="abcdef";
m=2;
n=4;
|
a=a .substring(0 ,m)+a.substring(n+1);
|
abf
|
|
Remove chars from index 'n' onwards (inclusive)
|
a="abcdefghi";
n=3;
|
a=a.substring(0,n);
|
abc
|
|
Remove chars up to index 'n' (inclusive)
|
a="abcdefghi";
n=3;
|
a=a.substring(n+1);
|
efghi
|
Trim
|
Trim leading and trailing white space
|
a=" abc def ";
|
a=a.trim();
|
abc def
|
Sort
|
Sort in ascending order
|
a="cadefb";
|
ca=a.toCharArray(); Arrays.sort(ca); a=String.valueOf(ca);
|
abcdef
|
|
Reverse
|
a="abcdefghi";
|
a=(new StringBuffer(a)) .reverse().toString();
|
ihgfedcba
|
Convert case
|
Convert to lower case
|
a="ABCDEFGHI";
|
a=a.toLowerCase();
|
abcdefghi
|
|
Convert to upper case
|
a="abcdefghi";
|
a=a.toUpperCase();
|
ABCDEFGHI
|
|
