javascript - 在React Native中找到数组元素的总和

Question

在这里，我正在映射financialTransactionDetail数组并填充数据。值(value)观正在变好。现在，我必须获取TransactionAmount的总和，就像数组的长度为3就有3 TransactionAmount的总和一样，我必须找到1050 + 1050 + 1050 = 3150的总和。我尝试使用load hash，但未获得正确的值。
请帮忙 。

// Below is the array value 
financialTransactionDetail: Array(3)
0:
AdjustedAmount: "0"
NetTransactionAmount: "1050"
TransactionAmount: 1050
1:
AdjustedAmount: "0"
NetTransactionAmount: "1050"
TransactionAmount: 1050

2:
AdjustedAmount: "0"
NetTransactionAmount: "1050"
Status: "Unpaid"
TransactionAmount: 1050

__typename: "FinancialTransactionDetail"
///////////////////////     
<Tab heading="INVOICE SPECIFIC">
                      { !_.isEmpty(financialTransactionDetail.financialTransactionDetail) && financialTransactionDetail.financialTransactionDetail.map(
                        (data, index) => {
                         // this.state.sum+= Sum(parseInt( data.TransactionAmount));
                          this.state.transactionAmount=_.sum(data.TransactionAmount) ;
                          console.log("sum data ",this.state.transactionAmount);
                          return(
                            <View key={index} style={{flexDirection:'row', padding:10, alignItems:'center', justifyContent:'space-between'}}>
                          <View style={{paddingRight:10, marginRight:10}}>
                            <CheckBox style={styles.checkBox} color="#00678f" checked={this.state.isChecked} onPress={() =>this.handleChange()}/>
                          </View>
                          <View style={{flexDirection:'column',flex:1, padding:10, borderWidth:1, borderColor:'lightgrey', borderRadius:10}}>
                            <View style={{flexDirection:'row', alignItems:'center'}}>
                              {!this.state.isChecked && <RegularText text={`₦ ${data.TransactionAmount}`} style={{paddingBottom:10, paddingRight:5}}/>}
                              <SmallText text="From 1-Jan-2019 to 31-Jan-2019" style={{paddingBottom:10}}/>
                            </View>
                            {this.state.isChecked && 
                            <RegularText text={`₦ ${data.TransactionAmount}`} style={{borderColor: '#00fff', borderBottomWidth:1}}>
                              </RegularText>
                              /* <Input
                                value={this.state.transactionAmount}
                                onChangeText={(text) => this.setState({value1:text})}
                              /> */
                            }
                          </View>
                        </View>

Answer 1

您可以使用纯JavaScript方法reduce对值求和:

let financialTransactionDetail = 
[
    {
        AdjustedAmount: "0",
        NetTransactionAmount: "1050",
        TransactionAmount: 1050
    },
    {
        AdjustedAmount: "0",
        NetTransactionAmount: "1050",
        TransactionAmount: 1050
    },
    {
        AdjustedAmount: "0",
        NetTransactionAmount: "1050",
        Status: "Unpaid",
        TransactionAmount: 1050
    }
];

let sum = financialTransactionDetail.reduce((a, c) => { return a + c.TransactionAmount}, 0);
console.log('sum: ', sum)