Question

如何只输入正数，如果我输入负数，它会自动转换为正数这个代码我有怎样编辑它

import {Directive, EventEmitter, HostListener, Output} from 'angular2/core';
import {Observable} from 'rxjs/Observable';

@Directive({
  selector: '[draggable]'
})
export class DraggableDirective {

  @Output() mousedrag: Observable<{x: number, y: number}>;
  @Output() dragend = new EventEmitter<void>();
  mousedown = new EventEmitter<MouseEvent>();
  mousemove = new EventEmitter<MouseEvent>();
  dragActive = false;

  @HostListener('document:mouseup', ['$event'])
  onMouseup(event) {
    if(this.dragActive) {
      this.dragend.emit(null);
      this.dragActive = false;
    }
  }

  @HostListener('mousedown', ['$event'])
  onMousedown(event: MouseEvent) {
    this.mousedown.emit(event);
  }

  @HostListener('document:mousemove', ['$event'])
  onMousemove(event: MouseEvent) {
    if(this.dragActive) {
      this.mousemove.emit(event);
      return false;
    }
  }

  constructor() {
    this.mousedrag = this.mousedown.map((event) => {
      this.dragActive = true;
      return { x: event.clientX, y: event.clientY };
    }).flatMap(mouseDownPos => this.mousemove.map(pos => {
      return { x: pos.clientX - mouseDownPos.x, y: pos.clientY - mouseDownPos.y };
    }).takeUntil(this.dragend));
  }
}

Answer 1

GrumpyCrouton＆gt;您尝试转换为正数的变量是什么？

M.Alhaddad＆gt; @GrumpyCrouton product_qty

这很简单。

只需对变量使用abs()。

$product_qty = abs($cart_itm["product_qty"]);

注意：abs()适用于(PHP 4, PHP 5, PHP 7)

“将数字转换为正数”只是获得它的绝对值。

文档： PHP function.abs

验证引擎将负数转换为正数

1 个答案: