为什么在使用php json_encode进行转换时，＆符号会成为html代码

Question

I have an array in php that I am parsing to a javascript. My problem is that some of the strings in the array contain ampersands, and they become & instead of & in the javascript. Here is a simple example to illustrate my issue:

<? $titles = json_encode(array("H&M", "Tesco")); ?>

<script>
var titles = <? echo $titles; ?>; 
console.log(titles[0]);
</script>

the log reads:

H&M

Answer 1

It happens because that's how the HTTP protocol divides the elements of a GET or POST transaction. This will solve the problem on the javascript end:

var convertAmpersand = function(str) {
  return str.replace(/&/g, "\&");
};

console.log(convertAmpersand(titles[0]));