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docs/ccxt/wiki/examples/js/looping-over-specific-symbols-of-all-exchanges.md

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+- [Looping Over Specific Symbols Of All Exchanges](./examples/js/)
+
+
+ ```javascript
+ 
+
+import ccxt from '../../js/ccxt.js';
+import asTable from 'as-table';
+import ololog from 'ololog';
+import ansicolor from 'ansicolor';
+
+const log       = ololog.configure ({ locate: false }), verbose   = process.argv.includes ('--verbose');
+
+ansicolor.nice
+
+//-----------------------------------------------------------------------------
+
+;(async () => {
+
+    const exchanges = {};
+    const symbols = [ 'ETH/BTC', 'XRP/BTC', 'BTC/USDT' ]
+
+    for (let symbol of symbols) {
+
+        for (let exchangeId of ccxt.exchanges) {
+
+            let exchange = undefined
+
+            try { // try creating the exchange instance first and handle errors if any
+
+                // check if we have created an instance of this exchange already
+
+                exchange = exchanges[exchangeId]
+
+                if (exchange === undefined) {
+
+                    // create the exchange instance
+                    exchange = new ccxt[exchangeId] ()
+                }
+
+                exchanges[exchangeId] = exchange // save it for later use
+
+            } catch (e) {
+
+                log.red ('Could not create exchange', exchangeId + ':', e.constructor.name, e.message)
+
+                // uncomment the following line to interrupt program execution on error
+                // or leave it commented out to do nothing
+
+                // process.exit ()
+
+            }
+
+            if (exchange !== undefined) {
+
+                // preload all markets first, as explained in the Manual:
+                // https://github.com/ccxt/ccxt/wiki/Manual#loading-markets
+
+                // add error/exception handling as required by the Manual:
+                // https://github.com/ccxt/ccxt/wiki/Manual#error-handling
+
+                try {
+
+                    await exchange.loadMarkets ();
+
+                } catch (e) {
+
+                    log.red ('Could not load markets from', exchange.id + ':', e.constructor.name, e.message)
+                    continue; // skip this exchange if markets failed to load
+
+                }
+
+                for (let symbol of symbols) {
+
+                    console.log (exchange.id, symbol)
+
+                    // add error/exception handling as required by the Manual:
+                    // https://github.com/ccxt/ccxt/wiki/Manual#error-handling
+
+                    try { // try fetching the ticker for a symbol existing with that exchange
+
+                        const ticker = await exchange.fetchTicker (symbol)
+                        log.green (ticker)
+
+                    } catch (e) { // catch the error (if any) and handle it or ignore it
+
+                        log.red ('Could not fetch', symbol, 'ticker from', exchange.id + ':', e.constructor.name, e.message)
+
+                    }
+                }
+            }
+        }
+    }
+
+}) ()
+ 
+```