Analysis of common methods of String in Javascript

// length attribute: gets the number of characters in the string.  var s='Love is like a gust of wind';
  alert();
// charAt(index) method: get the character at the specified index position, the index starts from 0  var s1='I don't want to miss you anymore';
  alert((4));//think// indexOf('e',startIndex) method: Get the location where the specified string first appears.  startIndex means the search starts from the first one.  var s2='I realized that it was another autumn afterwards';
  alert(('Pass',3));//6
// split('delimit',limit); returns a string to an array according to the delimiter.//limit indicates the maximum length of the array to be returned (customizable).  var s3='Quick Horse|In the World|Fight';
  alert(('|',2));
//Segmented with |, split the string, display it as an array, and contains only two elements  var arr=('|',3);//Three elements  for(var i=0;i<;i++){
  alert(arr[i]);
  }
// substr(startIndex,len) starts from startIndex (including), and then intercepts len characters.  var s4='A black sweater';
  alert((4,2));// Sweater, starting from subscript 4, including 4, and two characters are intercepted later// substring(startIndex, stopIndex) starts with startIndex,// Intercept the stopIndex position (excluding the characters where stopIndex is located)  var s5='Fireworks are easy to get cold and people are easy to separate';
  alert((1,4));//Flowers are easy to cool, starting from 1 to 4, excluding 1 and 4// toUpperCase() converts uppercase, toLowerCase(); converts lowercase  var s6='What are you kidding me';
  alert(());
  alert(());