Method: String#insert

Defined in:
string.c

#insert(index, other_str) ⇒ String

Inserts other_str before the character at the given index, modifying str. Negative indices count from the end of the string, and insert after the given character. The intent is insert aString so that it starts at the given index.

"abcd".insert(0, 'X')    #=> "Xabcd"
"abcd".insert(3, 'X')    #=> "abcXd"
"abcd".insert(4, 'X')    #=> "abcdX"
"abcd".insert(-3, 'X')   #=> "abXcd"
"abcd".insert(-1, 'X')   #=> "abcdX"

Returns:



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# File 'string.c', line 3840

static VALUE
rb_str_insert(VALUE str, VALUE idx, VALUE str2)
{
    long pos = NUM2LONG(idx);

    if (pos == -1) {
  return rb_str_append(str, str2);
    }
    else if (pos < 0) {
  pos++;
    }
    rb_str_splice(str, pos, 0, str2);
    return str;
}