Angular equivalent of jQuery $.map?

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难免孤独
难免孤独 2021-01-03 18:02

I\'m transitioning from relying on jQuery to building apps in AngularJS. It\'s recommended in a number of places to not mix jQuery and Angular code.

One thi

2条回答
  •  难免孤独
    2021-01-03 18:29

    Check here: https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/Array/map

    Mozilla has supplied an Array.map polyfill for unsupported browsers

    if (!Array.prototype.map) {
      Array.prototype.map = function(callback, thisArg) {
    
        var T, A, k;
    
        if (this == null) {
          throw new TypeError(" this is null or not defined");
        }
    
        // 1. Let O be the result of calling ToObject passing the |this| value as the argument.
        var O = Object(this);
    
        // 2. Let lenValue be the result of calling the Get internal method of O with the argument "length".
        // 3. Let len be ToUint32(lenValue).
        var len = O.length >>> 0;
    
        // 4. If IsCallable(callback) is false, throw a TypeError exception.
        // See: http://es5.github.com/#x9.11
        if (typeof callback !== "function") {
          throw new TypeError(callback + " is not a function");
        }
    
        // 5. If thisArg was supplied, let T be thisArg; else let T be undefined.
        if (thisArg) {
          T = thisArg;
        }
    
        // 6. Let A be a new array created as if by the expression new Array(len) where Array is
        // the standard built-in constructor with that name and len is the value of len.
        A = new Array(len);
    
        // 7. Let k be 0
        k = 0;
    
        // 8. Repeat, while k < len
        while(k < len) {
    
          var kValue, mappedValue;
    
          // a. Let Pk be ToString(k).
          //   This is implicit for LHS operands of the in operator
          // b. Let kPresent be the result of calling the HasProperty internal method of O with argument Pk.
          //   This step can be combined with c
          // c. If kPresent is true, then
          if (k in O) {
    
            // i. Let kValue be the result of calling the Get internal method of O with argument Pk.
            kValue = O[ k ];
    
            // ii. Let mappedValue be the result of calling the Call internal method of callback
            // with T as the this value and argument list containing kValue, k, and O.
            mappedValue = callback.call(T, kValue, k, O);
    
            // iii. Call the DefineOwnProperty internal method of A with arguments
            // Pk, Property Descriptor {Value: mappedValue, : true, Enumerable: true, Configurable: true},
            // and false.
    
            // In browsers that support Object.defineProperty, use the following:
            // Object.defineProperty(A, Pk, { value: mappedValue, writable: true, enumerable: true, configurable: true });
    
            // For best browser support, use the following:
            A[ k ] = mappedValue;
          }
          // d. Increase k by 1.
          k++;
        }
    
        // 9. return A
        return A;
      };      
    }
    

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