如何给javascript函数中的一个变量喂一个参数来改变?

How to feed javascript function a variable in a parameter to change?

例如,我有这个代码:

  function verifyContents(fieldInfo, indicator){
    if (fieldInfo === ""){
      indicator = "You didn't enter anything in here";
      return;
    }
    else{
      indicator = "";
    };
  };

我想获取fieldInfo,检查它是否为空,并根据它改变输入到indicator中的变量。我只是这样称呼它:

verifyContents(formContents[0],usernameFieldIndicator);

你可以通过使用let myVar声明一个反应式svelte变量,所以这里你不需要将变量作为参数传递,直接使用它即可:

<script>
    let indicator = ""

    function verifyContents(fieldInfo){
      if (fieldInfo === ""){
        indicator = "You didn't enter anything in here";
      }
      else{
        indicator = "";
      };
    };
</script>

<button on:click={() => verifyContents("", indicator)}>verify!</button>
<p>{indicator}</p>

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