Js determines whether the data is an array or a string

There are many ways to determine whether the data is an array or a string, some common methods are listed below:

1. Use the typeof operator to determine the data type. If it is "string", the data is a string; if it is "object", you need to further determine whether it is an array.

function isStringOrArray(data) {
  if (typeof data === "string") {
    console.log("数据为字符串");
  } else if (typeof data === "object") {
    if (Array.isArray(data)) {
      console.log("数据为数组");
    }
  }
}

2. Use the instanceof operator to determine the data type. If it is String, the data is a string; if it is Array, the data is an array.

function isStringOrArray(data) {
  if (data instanceof String) {
    console.log("数据为字符串");
  } else if (data instanceof Array) {
    console.log("数据为数组");
  }
}

3. Use the Array.isArray() method to determine whether the data is an array.

function isStringOrArray(data) {
  if (Array.isArray(data)) {
    console.log("数据为数组");
  } else {
    console.log("数据为字符串");
  }
}

4. Use regular expressions to determine whether the data is a string.

function isStringOrArray(data) {
  if (/^[a-zA-Z]+$/.test(data)) {
    console.log("数据为字符串");
  } else {
    console.log("数据为数组");
  }
}