Question

我正在编写一个角度指令，它只允许用户在范围内的输入字段中输入数字。

html代码

<input non-negative-number range-min="1" range-max="5000" ng-model="number1">
     <input non-negative-number range-min="0" range-max="1000" ng-model="number2">

角度指示

angular.module("NumberDirective", [])
   .directive('nonNegativeNumber', function() {
    return {
        restrict: 'A',
        require: '?ngModel',

        link: function (scope, element, attrs, ngModel) {
            var lastVal = null;
            if (!ngModel) { return; }

            ngModel.$parsers.push(function(val) {

                lastVal = ngModel.$modelValue;
                var pattern = /[^0-9]+/g;
                var parsed = val.replace(pattern, '');
                if (parseInt(parsed) > parseInt(attrs.rangeMax)) { parsed = lastVal; }
                if (parseInt(parsed) < parseInt(attrs.rangeMin)) { parsed = lastVal; }
                if (val !== parsed) {
                    lastVal = parsed;
                    ngModel.$setViewValue(parsed);
                    ngModel.$render();
                }
                return parsed;
            });

            element.bind('keypress', function(event) {
                if(event.keyCode === 32) {
                    event.preventDefault();
                }
            });
        }
    };
   });

这工作正常，但我还需要正则表达式，不能在输入的开头键入两个零，

<00>如00,0000000000045,00000000000000000000000100

任何人都可以建议正确的正则表达式吗？

Answer 1

尝试

^[0]{0,1}[1-9]\d{0,}

^ asserts position at start of the string
Match a single character present in the list below [0]{0,1}
{0,1} Quantifier — Matches between zero and one times, as many times as possible, giving back as needed (greedy)
0 matches the character 0 literally (case sensitive)

Match a single character present in the list below [1-9]
1-9 a single character in the range between 1 (ASCII 49) and 9 (ASCII 57) (case sensitive)

\d{0,} matches a digit (equal to [0-9])
{0,} Quantifier — Matches between zero and unlimited times, as many times as possible, giving back as needed (greedy)

Global pattern flags
g modifier: global. All matches (don't return after first match)

自定义角度指令在开始时不允许两个或更多零的正则表达式

1 个答案: