使用 php 在大小写循环中增加字母

Question

我正在开发一个项目，我需要循环显示这样的字母：a，A，b，B ... z，Z，aa，Aa，aA，AA，bb ... zz，ZZ ... PHP。

是否有可能以可扩展的方式做到这一点？

Answer 1

不确定这就是您要找的吗？

$low = $low2 = range('a', 'z');
$upp = $upp2 = range('A', 'Z');

$arr = array();
foreach ($low as $val)
{
  $arr[] = $val;
  foreach ($low2 as $lval)
  {
    $arr[] = $val.$lval;
  }
}

foreach ($upp as $val)
{
  $arr[] = $val;
  foreach ($upp2 as $uval)
  {
    $arr[] = $val.$uval;
  }
}

foreach ($low as $val)
{
  foreach ($upp as $uval)
  {
    $arr[] = $val.$uval;
  }
}

foreach ($upp as $val)
{
  foreach ($low as $lval)
  {
    $arr[] = $val.$lval;
  }
}

Answer 2

计算排列是一项相当繁重的任务。这将专门针对计算包含所有小写和大写字母的集合的两个字符排列的情况（我还没有测试该函数，但您应该能够弄清楚它在做什么并修复任何错误，它会至少让你开始）。

function permutations($items)
{
  empty($items)?return array():$perms = array();
  for ($i = count($items)-1; $i > 0; --$i)
  {
    $perms[] = $items[0].$items[$i];
  }
  return array_merge($perms, permutations(array_slice($items,1)));
}

Answer 3

$lowercase 和 $uppercase 是分别保存 az 和 AZ 的 ASCII 值的数组。

根据需要进行修改。

<?php

    $lowercase = array(97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122);

    $uppercase = array(65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90);

    $i = 0;
    for($i; $i < 26; $i++) {
        echo chr($lowercase[$i]) . ", ";
        echo chr($uppercase[$i]) . ", ";
    }

    $i = 0;
    for($i; $i < 26; $i++) {
        echo chr($lowercase[$i]);
        echo chr($lowercase[$i]);
        echo ", ";
        echo chr($uppercase[$i]);
        echo chr($lowercase[$i]);
        echo ", ";
        echo chr($lowercase[$i]);
        echo chr($uppercase[$i]);
        echo ", ";
        echo chr($uppercase[$i]);
        echo chr($uppercase[$i]);
        echo ", ";
    }

?>

输出如下所示：

a, A, b, B, c, C, d, D, e, E, f, F, g, G, h, H, i, I, j, J, k, K, l, L, m, M, n, N, o, O, p, P, q, Q, r, R, s, S, t, T, u, U, v, V, w, W, x, X, y, Y, z, Z, aa, Aa, aA, AA, bb, Bb, bB, BB, cc, Cc, cC, CC, dd, Dd, dD, DD, ee, Ee, eE, EE, ff, Ff, fF, FF, gg, Gg, gG, GG, hh, Hh, hH, HH, ii, Ii, iI, II, jj, Jj, jJ, JJ, kk, Kk, kK, KK, ll, Ll, lL, LL, mm, Mm, mM, MM, nn, Nn, nN, NN, oo, Oo, oO, OO, pp, Pp, pP, PP, qq, Qq, qQ, QQ, rr, Rr, rR, RR, ss, Ss, sS, SS, tt, Tt, tT, TT, uu, Uu, uU, UU, vv, Vv, vV, VV, ww, Ww, wW, WW, xx, Xx, xX, XX, yy, Yy, yY, YY, zz, Zz, zZ, ZZ,

Answer 4

此代码写入一行包含 1 个字符宽的元素，然后写入一行包含 2 个字符宽的元素，等等。

对于每个宽度，它通过迭代字母并从 0 到 2 ^ 宽度计数并基于二进制位进行大写来打印所有排列。

e.g.
  00 = aa
  01 = aA
  10 = Aa
  11 = AA

(actually I have iterated bits from lowest to highest rank to get the order to match your example)

代码：

$maxwidth = 3;
for ( $width = 1; $width <= $maxwidth; $width++ ) {
    for ( $letter = ord('a'); $letter <= ord('z'); $letter++ ) {
        for ( $num = 0; $num < pow(2,$width); $num++ ) {
            for ( $bit = 0; $bit < $width; $bit++ ) {
                print ($num & pow(2, $bit)) ? strtoupper(chr($letter)) : chr($letter);  
            }
            print ','; 
        }
    }
    print "\n";
}

输出：

a,A,b,B,c,C,d,D,e,E,f,F,g,G,h,H,i,I,j,J,k,K,l ,L,m,M,n,N,o,O,p,P,q,Q,r,R,s,S,t,T,u,U,v,V,w,W,x,X ,y,Y,z,Z,
aa,Aa,aA,AA,bb,Bb,bB,BB,cc,Cc,cC,CC,dd,Dd,dd,DD,ee,Ee,eE,EE,ff,Ff,ff,FF,gg, Gg,gG,GG,hh,Hh,hH,HH,ii,Ii,iI,II,jj,Jj,jJ,JJ,kk,Kk,kk,KK,ll,Ll,lL,LL,mm,Mm, mM,MM,nn,Nn,nN,NN,oo,Oo,oO,OO,pp,Pp,pP,PP,qq,Qq,qQ,QQ,rr,Rr,rR,RR,ss,Ss,sS, SS,tt,Tt,tT,TT,uu,Uu,uU,UU,vv,Vv,vV,VV,ww,Ww,wW,WW,xx,Xx,xX,XX,yy,Yy,yY,YY, zz,Zz,zZ,ZZ,
aaa,Aaa,aAa,AAa,aaA,AaA,aAA,AAA,bbb,Bbb,bBb,BBb,bbB,BbB,bBB,BBB,ccc,CCC,ccCc,CCc,ccC,CCC,ccC,CCC,ddd, ddd、ddd、ddd、ddd、ddd、ddd、ddd、eee、eee、eee、eee、eee、eee、eeee、eee、fff、fff、fff、fff、fff、fff、fff、fff、ggg、ggg, ggg,ggg,ggG,ggg,ggg,ggg,hhh,hhhh,hHh,HHh,hhH,HhH,hHH,HHH,iii,Iii,iIi,IIIi,iii,IiI,iII,III,jjj,Jjj,jJj, JJj,jjJ,JjJ,jJJ,JJJ,kkk,Kkk,kKk,KKk,kkK,KkK,kKK,KKK,lll,Lll,lLl,LLl,llL,LlL,lLL,LLL,mmm,Mmm,mMm,MMm, mmM、MmM、mMM、MMM、nnn、Nnn、nNn、NNn、nnN、NnN、nNN、NNN、ooo、Ooo、oOo、OOo、ooO、OoO、oOO、OOO、ppp、ppp、ppp、ppp、ppp、 PpP,pPP,PPP,qqq,Qqq,qQq,QQq,qQQ,QqQ,qQQ,QQQ,rrr,Rrr,rRr,RRr,rrR,RrR,rRR,RRR,sss,Sss,sSs,SSs,ssS,SsS, sSS,SSS,ttt,Ttt,tTt,TTt,ttT,TtT,tTT,TTT,uuu,Uuu,uUu,UUu,uuU,UuU,uUU,UUU,vvv,Vvv,vVv,VVv,vvV,VvV,vVV, VVV,www,WWW,WWW,WWW,WWW,WWW,WWW,WWW,xxx,Xxx,xXx,XXx,xxX,XxX,xXX,XXX,yyy,Yyy,yYy,YYy,yyY,YyY,yYY,YYY, zzz,Zzz,zZz,ZZz,zzZ,ZzZ,zZZ,ZZZ,

Answer 5

当然。字母字符只需使用 $a++ 即可递增。为简单起见，如果只需要单倍或双倍长度，您可以......

$single_set = array(); // array holding single-character sequence
$double_set = array(); // array holding double-character sequence

for ($v1 = 'a', $v2 = 'A'; $v1 !== 'aa'; $v1++, $v2++) {
    $single_set[] = $v1;
    $single_set[] = $v2;
    $double_set[] = $v1 . $v1;
    $double_set[] = $v1 . $v2;
    $double_set[] = $v2 . $v1;
    $double_set[] = $v2 . $v2;
    }

$set = $single_set + $double_set; // combined array sequence