如何生成具有可变数量的空格的字符串，或者如何在字符串后不添加空格

Question

I need help to generate empty string with particular no of spaces.

I tried this,

String opCode=  " ";

for(int l=0;l<opCodelen;l++)
{
    opCode+= " " ;   
}
//opCodelen will get change every time

This worked but I want better solution.becoz using this I will have to use multiple loops for multiple columns.Is there any other way to do this?

Answer 1

Try String.format()

    int opCodelen = 5;
    String opCode = String.format("%" + opCodelen + "s", "");
    System.out.println("[" + opCode + "]");

output

[     ]

Answer 2

Another way (uglier but for many probably simpler) to solve it could be

• creating array of characters with same length as number of spaces you want to end up with,
• filling it with spaces
• and passing it as argument in String constructor.

Something like

char[] arr = new char[10]; // lets say length of string should be 10
Arrays.fill(arr, ' ');     // fill array with spaces
String mySpaceString = new String(arr);
System.out.println(">" + mySpaceString + "<");

output:

>          <