PHP 数字金额转换成英文金额

数据库存储的金额为阿拉伯数字，但产品需求中需要呈现给用户消费账单时带有英文的金额，于是调用此封装函数，可将阿拉伯数字金额转换成英文的金额。

 1 )
        {
            $commas = $commas - 1;
        }
       
        $words  = implode( ', ' , $words );
       
        //Some Finishing Touch
        //Replacing multiples of spaces with one space
        $words  = trim( str_replace( ' ,' , ',' , trim_all( ucwords( $words ) ) ) , ', ' );
        if( $commas )
        {
            $words  = str_replace_last( ',' , ' and' , $words );
        }
       
        return $words;
    }
    else if( ! ( ( int ) $num ) )
    {
        return 'Zero';
    }
    return '';
}

function trim_all( $str , $what = NULL , $with = ' ' )
{
    if( $what === NULL )
    {
        //  Character      Decimal      Use
        //  "\0"            0           Null Character
        //  "\t"            9           Tab
        //  "\n"           10           New line
        //  "\x0B"         11           Vertical Tab
        //  "\r"           13           New Line in Mac
        //  " "            32           Space

        $what   = "\\x00-\\x20";    //all white-spaces and control chars
    }

    return trim( preg_replace( "/[".$what."]+/" , $with , $str ) , $what );
}

function str_replace_last( $search , $replace , $str ) {
    if( ( $pos = strrpos( $str , $search ) ) !== false ) {
        $search_length  = strlen( $search );
        $str    = substr_replace( $str , $replace , $pos , $search_length );
    }
    return $str;
}