PHP numeric lowercase to uppercase function

When PHP converts Arabic numerals to Chinese, it is necessary to define a conversion algorithm:

<?php/converts a number to a Chinese character, such as 1210 to 1210 $num = "842105580",//nine-digit function del0 ($num)//Removes the 0 {return "" in front of the number field. Intval ($num); function n2c ($x)//single digit variable kanji {$arr _n = array ("0", "one", "two", "three", "four", "five", "six", "seven", "Eight", "IX", "ten"), return $arr _n[$x];} function n Um_r ($ABCD)//Read value (4 bits) {$arr = array (); $str = ""; The value of Chinese characters after reading is $flag = 0; Whether the bit is zero $flag _end = 1; Whether to end with "0" $size _r = strlen ($ABCD); for ($i =0; $i < $size _r; $i + +) {$arr [$i] = $ABCD {$i};} $arrlen = count ($arr); for ($j =0; $j < $arrlen; $j + +) {$ch = N2C ($arr [$arrlen-$j]);//forward to the Chinese character echo $ch; echo ""; if ($ch = = "0" && $flag = = 0) {//If it is the first 0 $flag = 1;//The bit is zero $str = $ch. $str;//Add Chinese character value string continue;} ElseIf ($ch = = "0") {//If it is not the first zero continue;} $flag = 0; This bit is not 0 switch ($j) {case 0: $str = $ch; $flag _end = 0; break;//First bit (end), no "0" end Case 1: $str = $ch. " Ten ". $str; Break Second Case 2: $str = $ch. " Hundred ". $str; Break Third Case 3: $str = $ch. " Thousand ". $str; Break Fourth bit} if ($flag _end = = 1)//If End with "0" {mb_internal_encoding ("UTF-8"); $str = Mb_substr ($STR, 0, Mb_strlen ($str)-1); Remove the "0"} return $str; } function Num2ch ($num)//Overall read conversion {$num _real = del0 ($num);//Remove the preceding "0" $numlen = strlen ($num _real); echo "numlen=". $numlen. " "; if ($numlen >= 9)//If full nine bits, read "million" bit {$y =substr ($num _real,-9, 1);//echo $y; $wsbq = substr ($num _real, 8, 4); $GSBQ = Subs TR ($num _real,-4); $a = Num_r (Del0 ($GSBQ)); $b = Num_r (Del0 ($WSBQ)). " Million "; $c = Num_r (Del0 ($y)). " Billion "; }elseif ($numlen <= 8 && $numlen >= 5)//if greater than or equal to "million" {$wsbq = substr ($num _real, 0, $numlen-4); $GSBQ = substr ( $num _real,-4); $a = Num_r (Del0 ($GSBQ)); $b = Num_r (Del0 ($WSBQ)). " Million "; $c = ""; }elseif ($numlen <= 4)//If it is less than or equal to "thousand" {$GSBQ = substr ($num _real,-$numlen); $a = Num_r (Del0 ($GSBQ)); $b = ""; $c = "";} $ch _ num = $c. $b. $a; return $ch _num; } echo $num. ""; Digital echo num2ch ($num); Chinese character echo ""; echo num2ch ("1240");?>

PHP numeric lowercase to uppercase function