Removing specific lines from a string by index-CodePudding

I have a String paragraph that always gonna have 6 lines, like the example below.

     val result= """
            ${getValue(A1)} ${getValue(A2)} ${getValue(A3)} ${getValue(A4)} ${getValue(A5)} 
            ${getValue(B1)} ${getValue(B2)} ${getValue(B3)} ${getValue(B4)} ${getValue(B5)} 
            ${getValue(C1)} ${getValue(C2)} ${getValue(C3)} ${getValue(C4)} ${getValue(C5)} 
            ${getValue(D1)} ${getValue(D2)} ${getValue(D3)} ${getValue(D4)} ${getValue(D5)} 
            ${getValue(E1)} ${getValue(E2)} ${getValue(E3)} ${getValue(E4)} ${getValue(E5)} 
            ${getValue(F1)} ${getValue(F2)} ${getValue(F3)} ${getValue(F4)} ${getValue(F5)} 
        """.trimIndent()

getValue returns only one char, so the output is always something like this:

A A A A A
B B B B B 
C C C C C
D D D D D
E E E E E
D D D D D

What I want is a way to remove specific lines from the past example by the line index.

For example I want an extention function that let me do this result.deleteLinesAt(3,5) and it will output like this:

A A A A A
B B B B B 
C C C C C
E E E E E

If this is not acheivable, can I find a way to remove the last N lines from a string paragraph

For example I want to type result.dropLastLines(2) and it will output like this:

A A A A A
B B B B B 
C C C C C
D D D D D

CodePudding user response：

val text = """
A A A A A
B B B B B
C C C C C
D D D D D
E E E E E
F F F F F
""".trimIndent()

fun String.deleteLinesAt(vararg lineNumbers: Int): String {
  return this
    .trim()
    .split("\n")
    .filterIndexed { index, _ -> index   1 !in lineNumbers }
    .joinToString("\n")
}

val result = text.deleteLinesAt(3, 5)

And for dropping last lines:

val text = """
A A A A A
B B B B B
C C C C C
D D D D D
E E E E E
F F F F F
""".trimIndent()

fun String.dropLastLines(countOfLines: Int): String {
  return this
    .trim()
    .split("\n")
    .dropLast(countOfLines)
    .joinToString("\n")

}

val result = text.dropLastLines(2)