如何检查给定的字符串是否包含另一个子字符串？

Question

如何检查给定的字符串是否包含另一个子字符串？

fun isFieldRepeated(jsonIn: String, field:String): Boolean { 
  var count: Int = 0; 
  while (jsonIn.indexOf(field) > -1) { 
       jsonIn = jsonIn.substring(jsonIn.indexOf(field)+field.length(),jsonIn.length()); 
       count++;  
  } 
  if(count>1) 
   return true; 
  return false; 
 }

Answer 1

我会简化它

fun isFieldRepeated(jsonIn: String, field:String): Boolean =
  jsonIn.firstIndexOf(field) != jsonIn.lastIndexOf(field)

Answer 2

fun isFieldRepeated(jsonIn: String, field: String): Boolean {
  return jsonIn.windowed(field.length) { it == field }.count { it } > 1
}

或作为扩展功能：

fun String.isFieldRepeated(field: String) = windowed(field.length) { it == field }.count { it } > 1

...例如，例如这样：

println("abcdefghcdij".isFieldRepeated("cd"))