I have a string array which has k elements. I want to print them out using System.out.format, but the issue is that I do not know k. So essentially, I want to use something like:
System.out.format("%s %s ... k times", str1, str2, ... strk);
(where k is a variable)
I was looking through the java documentation, but could not find a way to do this. Is there a simple way out?
Thanks!
you can use
System.out.format("%s". Arrays.toString(your_array));
[ and ] contained within the string which we do not want?Java 8:
String formatted = Stream.of(arrayOfStrings)
.collect(Collectors.joining(",","[","]"));
String formatted = Stream.of(arrayOfSomethingElse)
.map(Object::toString)
.collect(Collectors.joining(",","[","]"));
Use a loop:
for (String s : array) {
System.out.print(String.format("%s ", s));
}
System.out.println();
You can use String.join() to format your array to your desired result.
System.out.println(String.join(" ", array));
for(int i = 0; i < array.length; i++) {
System.out.print("%s ", array[i]);
}
Try:
StringBuilder sb = new StringBuilder();
for(String s : myArray){
sb.append(s).append(" ");
}
sb.append(myArray.length).append(" times");
System.out.println(sb.toString()); // print the string
Do you simply want to concatenate k strings with a space between each of the strings? You don't need System.out.format for that. You could simply create a loop to concatenate them together with a StringBuilder:
public String concatStrings(String... s) {
StringBuilder sb = new StringBuilder();
if (s.length > 0) {
sb.append(s[0]);
for (int i = 1; i < s.length; i++) {
sb.append(' ').append(s[i]);
}
}
return sb.toString();
}
I want to specify the number of characters that I want for each string. Something like %15s
That will only specify the padding for each String. If the String length is less than the value specified in the format specifier, then the full String is used. You could use substring
void displayArray(String[] str, int characters) {
for (String s: str) {
System.out.print(s.substring(0, Math.min(s.length(), characters)) + " ");
}
System.out.println();
}
That's typical toolbox code - code you often use and reuse, and best keep in a static-access utility class (such as StringUtil). Here's a generic function that works on all kinds of non-primitive arrays, and lets you specify the separator (space, comma, slash, whatever):
public static <T> void print (PrintStream out, String separator, T... elements) {
for (int i = 0; i < elements.length; i++) {
if (i > 0) {
out.print(separator);
}
out.print(elements[i]);
}
}
Example Usage:
String[] s = {"A", "B", "C", "D", "E"};
Integer[] n = {1, 2, 3, 4, 5}; //non-primitive
print(System.out, " ", s);
print(System.out, ", ", n);
Arrays.toString()is probably what you are looking for.