如何在不使用诸如“，”之类的内置函数的情况下从该字符串中删除最后一个逗号(，）；rtrim”；以及“；substr”； - how to remove last comma (,) from this string without using built-in functions like "rtrim" and "substr"

how to remove last comma (,) from this string without using built-in functions like "rtrim" and "substr"

如何从数组中删除最后一个逗号（，）？而不使用像rtrim和substr 这样的内置功能

    public function update( $table_name="", $fields_value=array(), $where="" ){
    //if( $table_name == "" || empty($fields_value) ||  $where == "" ) return false; 
    $fields_values = array(
        'name' => 'Vikrant',
        'class' => 'MCA',
        'Section' => 'a',
        'Subject' => 'Ele'
    );
    $column_value_string = "";
    foreach( $fields_values as $col_name => $col_value ) {
        $column_value_string .= " `$col_name`='$col_value' ,";
    }
    echo rtrim($column_value_string,",")."<br><br><br><br>";
    return;

要创建逗号分隔的列表，请将内容放入数组中，然后implodeit:

$column_value = array();
foreach( $fields_values as $col_name => $col_value ) {
    $column_value []= "`$col_name`='$col_value'";
}
$column_value_string = implode(", ", $column_value);

还要注意，动态生成SQL命令时必须转义值。

您可以在循环中使用计数器来完成此操作尝试

$fields_values = array(
        'name' => 'Vikrant',
        'class' => 'MCA',
        'Section' => 'a',
        'Subject' => 'Ele'
);
$count = count($fields_values);
$i=1;
$column_value_string = "";
foreach( $fields_values as $col_name => $col_value ) {
  $column_value_string .= " `$col_name`='$col_value'";
  if($i <$count) {
    $column_value_string .= ',';
  }
  $i++;
}
echo  $column_value_string;

输出：-

`name`='Vikrant', `class`='MCA', `Section`='a', `Subject`='Ele'

 $array = explode(",",$ TheArray);
 $array = implode(",", $array);

简短、简单。。

D_6

Hope this will help you......

    public function update( $table_name="", $fields_value=array(), $where="" ){ 
    $fields_values = array(
        'name' => 'Vikrant',
        'class' => 'MCA',
        'Section' => 'a',
        'Subject' => 'Ele'
    );
    $column_value_string = array();
    foreach( $fields_values as $col_name => $col_value ) {
        $column_value_string[] = " `$col_name`='$col_value'";
    }
    echo implode(',',$column_value_string);

您可以通过以下获得所需的结果

public function update( $table_name="", $fields_value=array(), $where="" ){
    //if( $table_name == "" || empty($fields_value) ||  $where == "" ) return false; 
    $fields_values = array(
        'name' => 'Vikrant',
        'class' => 'MCA',
        'Section' => 'a',
        'Subject' => 'Ele'
    );
    $column_value_string = "";
    foreach( $fields_values as $col_name => $col_value ) {
        $column_value_string .= ($column_value_string == ""?'':', ')." `$col_name`='$col_value'";
    }
    echo $column_value_string."<br><br><br><br>";
    return;
}