Nodejs String Starts With startsWith(substr)

Method Source Code

String.prototype.startsWith = function(substr) {
    for (var i = 0; i < substr.length; i++) {
        if (this[i] !== substr[i]) {
            return false;
        }/*w w  w .  j  av a  2s. co  m*/
    }
    return true;
}

Related

1. startsWith(str, ignoreCase)

   String.prototype.startsWith = function(str, ignoreCase) {
     return (ignoreCase ? this.toUpperCase() : this)
       .indexOf(ignoreCase ? str.toUpperCase() : str) == 0;
   };
   

2. startsWith(string)

   String.prototype.startsWith = function (string) {
     var index = arguments.length < 2 ? 0 : arguments[1];
     return this.slice(index).indexOf(string) === 0;
   };
   

3. startsWith(string)

   String.prototype.startsWith = function (string) {
     var index = arguments.length < 2 ? 0 : arguments[1];
     return this.slice(index).indexOf(string) === 0;
   };
   

4. startsWith(string)

   String.prototype.startsWith = function(string){
     if (typeof(string) !== "string") {
       throw new Error("Input argument was not a string");
     } else if (this.substring(0, string.length) === string) {
       return true;
     } else {
       return false;
   };
   ...
   

5. startsWith(string)

   String.prototype.startsWith = function (string){
     return this.indexOf(string) === 0;
   };
   

6. startsWith(substr)

   String.prototype.startsWith = function(substr) {
     return (this.indexOf(substr) == 0);
   };
   

7. startsWith(substring)

   String.prototype.startsWith = function (substring) {
       var stringCut = this.substring(0, substring.length);
       return stringCut === substring;
   

8. startsWith(substring)

   "use strict";
   String.prototype.startsWith  = function(substring) {
       var substringLength = substring.length;
       if (substringLength > this.length) {
           return false;
       var i;
       for (i = 0; i < substringLength; i += 1) {
           if (substring[i] !== this[i]) {
   ...
   

9. startsWith(substring)

   String.prototype.startsWith = function(substring) {
       var compareString = this.substring(0, substring.length);
       return compareString === substring;
   };