无法理解语法错误

Question

I have a script that "remember" the values in the input fields after a submit.

var previousData = <? php echo json_encode($_POST, JSON_UNESCAPED_UNICODE); ?> ;
for (item in previousData) {
    if (previousData.hasOwnProperty(item)) {
        // Set the value to the input with same name
        $('input[name=' + item + ']').val(previousData[item]);
        $('select[name=' + item + ']').val(previousData[item]);
    }
}

The problem is that I get a syntax error:

SyntaxError: syntax error

var previousData = ;

When I remove JSON_UNESCAPED_UNICODE, it works perfect. Why?

Answer 1

Wrap your code in quotes:

    var previousData = '<?php echo json_encode($_POST,JSON_UNESCAPED_UNICODE); ?>'; //single or double quotes here
    for (item in previousData) {
    if (previousData.hasOwnProperty(item)) {
      // Set the value to the input with same name
      $("input[name='"+item+"']").val(previousData[item]);   //Double quotes here
      $("select[name='"+item+"']").val(previousData[item]);   //Double quotes here