Tag: string

java

How to convert java string array to string with delimiter

- by Tirex - Leave a Comment

Using String.join method (from java 8)

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String[] array = new String[] { "a", "b", "c" };
String joined2 = String.join(",", array);

Using simple for-loop expression

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StringBuilder sb = new StringBuilder();
for (String n : name) {
    if (sb.length() > 0) sb.append(',');
    sb.append("'").append(n).append("'");
}
return sb.toString();

 

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java

How to convert an int to a formatted string in java

- by Tirex - Leave a Comment

Using java.util.formatter

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StringBuilder sb = new StringBuilder();
// Send all output to the Appendable object sb
Formatter formatter = new Formatter(sb, Locale.US);
 
// Explicit argument indices may be used to re-order output.
formatter.format("%4$2s %3$2s %2$2s %1$2s", "a", "b", "c", "d")
// -> " d  c  b  a"
 
// Optional locale as the first argument can be used to get
// locale-specific formatting of numbers.  The precision and width can be
// given to round and align the value.
formatter.format(Locale.FRANCE, "e = %+10.4f", Math.E);
// -> "e =    +2,7183"
 
// The '(' numeric flag may be used to format negative numbers with
// parentheses rather than a minus sign.  Group separators are
// automatically inserted.
formatter.format("Amount gained or lost since last statement: $ %(,.2f",
            balanceDelta);
// -> "Amount gained or lost since last statement: $ (6,217.58)"

See the Formatter docs for other modifiers.

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java

How to repeat string ‘n’ times in java?

- by Tirex - Leave a Comment

Suppose you have the string ‘qwe’ and you need to repeat string ‘n’ times. Here’s how to do it: Using java 8 stream api

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String newString = Collections.nCopies(3, "qwe").stream().collect(Collectors.joining(""));
 
String newString = Stream.generate(() -> "qwe").limit(3).collect(Collectors.joining());
 
String newString = String.join("", Collections.nCopies(n, s));

Using String.format

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String s = "qwe";
int n = 3;
//this line print 'qweqweqwe'
String newString = String.format("%0" + n + "d", 0).replace("0", s);

Let us examine …

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