From 4b1a9203c547c019fc5398082ae19a3f3d4c3efe Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:41:15 -0500 Subject: initial commit --- .../global_objects/string/repeat/index.html | 286 +++++++++++++++++++++ 1 file changed, 286 insertions(+) create mode 100644 files/de/web/javascript/reference/global_objects/string/repeat/index.html (limited to 'files/de/web/javascript/reference/global_objects/string/repeat') diff --git a/files/de/web/javascript/reference/global_objects/string/repeat/index.html b/files/de/web/javascript/reference/global_objects/string/repeat/index.html new file mode 100644 index 0000000000..6008654521 --- /dev/null +++ b/files/de/web/javascript/reference/global_objects/string/repeat/index.html @@ -0,0 +1,286 @@ +--- +title: String.prototype.repeat() +slug: Web/JavaScript/Reference/Global_Objects/String/repeat +tags: + - ECMAScript 2015 + - JavaScript + - Méthode + - Prototype + - Referenz + - String +translation_of: Web/JavaScript/Reference/Global_Objects/String/repeat +--- +
{{JSRef}}
+ +

Die repeat()-Funktion erzeugt und gibt eine Zeichenkette zurück, die die spezifizierte Anzahl von Kopien der angegebenen Zeichenkette aneinandergereiht enthält.

+ +

Syntax

+ +
str.repeat(Anzahl);
+
+ +

Parameter

+ +
+
Anzahl
+
Eine Zahl zwischen 0 und +∞: [0, +∞), die die Anzahl Kopien der Ursprungszeichenkette in der neu erzeugten Zeichenkette definiert.
+
+ +

Rückgabeergebnis

+ +

Eine neue Zeichenkette mit der angegebenen Anzahl an Kopien der vorgegebenen Zeichenkette.

+ +

Ausnahmen

+ + + +

Beispiele

+ +
'abc'.repeat(-1);   // Parameterfehler
+'abc'.repeat(0);    // ''
+'abc'.repeat(1);    // 'abc'
+'abc'.repeat(2);    // 'abcabc'
+'abc'.repeat(3.5);  // 'abcabcabc' (Anzahl wird in einen ganzzahligen Integer umgewandelt)
+'abc'.repeat(1/0);  // Parameterfehler
+
+({ toString: () => 'abc', repeat: String.prototype.repeat }).repeat(2);
+// 'abcabc' (repeat() ist eine generische Methode)
+
+ +

Polyfill

+ +

Diese Funktion wurde zur ECMAScript 2015 Spezifikation hinzugefügt und steht unter Umständen noch nicht in allen JavaScript-Implementierungen zur Verfügung. Bedarfsweise können Sie die Methode String.prototype.repeat() durch folgenden Code zur Verfügung stellen:

+ +
if (!String.prototype.repeat) {
+  String.prototype.repeat = function(count) {
+    'use strict';
+    if (this == null) {
+      throw new TypeError('can\'t convert ' + this + ' to object');
+    }
+    var str = '' + this;
+    count = +count;
+    if (count != count) {
+      count = 0;
+    }
+    if (count < 0) {
+      throw new RangeError('repeat count must be non-negative');
+    }
+    if (count == Infinity) {
+      throw new RangeError('repeat count must be less than infinity');
+    }
+    count = Math.floor(count);
+    if (str.length == 0 || count == 0) {
+      return '';
+    }
+    // Ensuring count is a 31-bit integer allows us to heavily optimize the
+    // main part. But anyway, most current (August 2014) browsers can't handle
+    // strings 1 << 28 chars or longer, so:
+    if (str.length * count >= 1 << 28) {
+      throw new RangeError('repeat count must not overflow maximum string size');
+    }
+    var rpt = '';
+    for (var i = 0; i < count; i++) {
+      rpt += str;
+    }
+    return rpt;
+  }
+}
+
+ +

Polyfill ES5

+ +
//#es5
+'use strict';
+(function(win){
+ var typeOf=(function(w){var f=function f(x){return typeof(x)},o=w.Symbol,p;if(o && typeof(o)==='function' && typeof(o.iterator)==='symbol'){p=o.prototype;f=function(x){return x && x.constructor===o && x!==p?'symbol':typeof x}};return f})(win),
+ exist=function(o,p,t){return p in o && typeOf(o[p])===t};
+ (function(w){
+    var o=w.String.prototype;
+    if(!exist(o,'repeat','function')){o.repeat=(function(A,E){return function(n){var i=n>>0,s=this,l=s.length,j;if(i===0||l<1){s=''}else{j=268435456;if(i<0||i>=j||i*l>j){throw new RE('Invalidcountvalue')}else if(i>0){s=A(++i).join(s)}};return s}})(w.Array,w.RangeError)};
+ })(win);
+})(window);
+
+//test:
+console.clear();
+console.log(
+'abc'.repeat(false),//''
+'abc'.repeat({}),//''
+'abc'.repeat([]),//''
+'abc'.repeat(['']),//''
+'abc'.repeat([0]),//''
+'abc'.repeat([0,1]),//''
+'abc'.repeat([1,1]),//''
+'abc'.repeat(0),//''
+'abc'.repeat(.6),//''
+'abc'.repeat(true),//'abc'
+'abc'.repeat(1),//'abc'
+'abc'.repeat(2),//'abcabc'
+'abc'.repeat([2]),//'abcabc'
+'abc'.repeat(3.5),//'abcabcabc'
+''.repeat(2)//''
+);
+console.log(
+'abc'.repeat(-Infinity),//RangeError: Invalid count value
+'abc'.repeat(Infinity),//RangeError: Invalid count value
+'abc'.repeat(1/0),//RangeError: Invalid count value
+'abc'.repeat(-1)//RangeError: Invalid count value
+);
+
+/*
+es5 src:
+'use strict';
+(function(win){
+
+ var typeOf=(function(w){var f=function f(x){return typeof(x)},o=w.Symbol,p;if(o && typeof(o)==='function' && typeof(o.iterator)==='symbol'){p=o.prototype;f=function(x){return x && x.constructor===o && x!==p?'symbol':typeof x}};return f})(win),
+ exist=function(o,p,t){return p in o && typeOf(o[p])===t};
+
+ (function(w){
+    var o=w.String.prototype;
+    if(!exist(o,'repeat','function')){
+        o.repeat=(function(A,E){
+            return function(n){
+                var i=n>>0,s=this,l=s.length,j;
+                if(i===0||l<1){s=''}else{
+                    j=268435456;
+                    if(i<0||i>=j||i*l>j){throw new RE('Invalidcountvalue')}else if(i>0){s=A(++i).join(s)}
+                };
+                return s
+            };
+        })(w.Array,w.RangeError);
+    };
+    //..
+ })(win);
+
+})(window);
+*/
+
+ +

Polyfill ES6

+ +
//#es6
+
+(w=>{
+
+    const typeOf=(o=>{let f=x=>typeof x;if(o && 'function'===typeof o){const s='symbol';if(s===typeof o.iterator){const p=o.prototype;f=x=>x && x.constructor===o && x!==p?s:typeof x}};return f})(w.Symbol),
+
+    exist=(o,p,t)=>p in o && typeOf(o[p])===t;
+
+    (o=>{
+
+        if(!exist(o,'repeat','function')){const A=w.Array,E=w.RangeError;o.repeat=function(n){var i=n>>0,s='';if(i!==0){let t=this;const l=t.length;if(l!==0){if(i<0||i>=(t=268435456)||i*l>t){throw new E('Invalid count value')}else if(i>0){s=A(++i).join(t)}}};return s}};
+
+    })(w.String.prototype);
+
+})(window);
+
+/*
+
+es6 src:
+
+(w=>{
+
+    const typeOf=(o=>{let f=x=>typeof x;if(o && 'function'===typeof o){const s='symbol';if(s===typeof o.iterator){const p=o.prototype;f=x=>x && x.constructor===o && x!==p?s:typeof x}};return f})(w.Symbol),
+
+    exist=(o,p,t)=>p in o && typeOf(o[p])===t;
+
+
+    (o=>{
+
+        if(!exist(o,'repeat','function')){
+
+            const A=w.Array;
+
+            o.repeat=function(n){var i=n>>0,s='';if(i!==0){let t=this;const l=t.length;if(l!==0){if(i<0||i>=(t=268435456)||i*l>t){throw new RangeError('Invalid count value')}else if(i>0){s=A(++i).join(t)}}};return s};
+
+        };
+
+        //..
+
+    })(w.String.prototype);
+
+
+})(window);
+
+*/
+
+
+//test:
+
+console.clear();
+
+console.log(
+
+'abc'.repeat(false),//''
+
+'abc'.repeat({}),//''
+
+'abc'.repeat([]),//''
+
+'abc'.repeat(['']),//''
+
+'abc'.repeat([0]),//''
+
+'abc'.repeat([0,1]),//''
+
+'abc'.repeat([1,1]),//''
+
+'abc'.repeat(0),//''
+
+'abc'.repeat(.6),//''
+
+'abc'.repeat(true),//'abc'
+
+'abc'.repeat(1),//'abc'
+
+'abc'.repeat(2),//'abcabc'
+
+'abc'.repeat([2]),//'abcabc'
+
+'abc'.repeat(3.5),//'abcabcabc'
+
+''.repeat(2)//''
+
+);
+
+console.log(
+
+'abc'.repeat(-Infinity),//RangeError: Invalid count value
+
+'abc'.repeat(Infinity),//RangeError: Invalid count value
+
+'abc'.repeat(1/0),//RangeError: Invalid count value
+
+'abc'.repeat(-1)//RangeError: Invalid count value
+
+);
+ +

Spezifikationen

+ + + + + + + + + + + + + + + + + + + +
SpezifikationStatusKommentar
{{SpecName('ES2015', '#sec-string.prototype.repeat', 'String.prototype.repeat')}}{{Spec2('ES2015')}}Erste Definition.
{{SpecName('ESDraft', '#sec-string.prototype.repeat', 'String.prototype.repeat')}}{{Spec2('ESDraft')}} 
+ +

Browserkompatibilität

+ + + +

{{Compat("javascript.builtins.String.repeat")}}

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