JavaScript simulation PHP Functions In_array_javascript Tips

JS to determine whether an element exists in a JS array, equivalent to the PHP language in the In_array function.

Array.prototype.s=string.fromcharcode (2); 
Array.prototype.in_array=function (e) { 
  var r=new RegExp (this. S+e+this. S); 
  Return (R.test) (this. S+this.join (this. S) +this. S)); 
}; 

Usage is as follows:

var arr=new Array (["B", 2, "a", 4, "Test"]); 
Arr.in_array (' test ')//Determines whether the test string exists in the ARR array, returns true otherwise false, and returns true here 

Note: This function is valid only for characters and numbers

There are similar functions in jquery: Http://docs.jquery.com/Utilities/jQuery.inArray

Its code is as follows:

function InArray (needle, haystack) {
  var length = haystack.length;
  for (var i = 0; i < length; i++) {
    if (haystack[i] = = needle) return true;
  }
  return false;
}

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